An audit by the Catholic Church's child protection watchdog has found only 12 Christian Brothers were convicted of crimes between 1975 and today.
A review of the congregation's files found that its initial response to the need to report abuse to the authorities was not systematic and was inadequate.
It revealed allegations were made against 325 brothers - only 50 of whom are still alive - with 870 complaints of abuse in the 38-year period, all of which have been reported to authorities.
The audit, carried out by the church's own watchdog, the National Board for Safeguarding Children in the Catholic Church, is one of eight being released today.
The latest and largest group of reviews by the oversight body scrutinise both current practice in two religious orders and six dioceses and the handling of all allegations received since January 1975.
In the Christian Brothers, the inspection board said one brother was returned to ministry after an allegation and only 12 brothers were convicted of offences against children.
It described the level of abuse from members of the order as substantial.
And it warned: "The number of convictions by the courts, compared to the numbers accused of child abuse, is significantly small."
In the 66 years between 1931 and 1997, the Christian Brothers received 92 allegations of abuse but in the subsequent 15 years, from 1998 to this year, they received 794 allegations.
Since internal reviews in 2007 and 2009, the safeguarding board said it is now satisfied that reports are made promptly.
The Christian Brothers said they accepted that a safeguarding deficit existed in the past.
"We want to learn from the mistakes of the past and to create a safe environment for all children and young adults," it said.
Successful investment of time by Down and Connor
The report into the diocese of Down and Connor said that the 14 allegations since the appointment of Bishop Noel Treanor five years ago have been properly managed.
It found that the diocese, which is the second largest on the island of Ireland, complied fully with 46 of 48 criteria.
The report said this indicates the very successful and effective investment of time and resources by the diocese in its Child Safeguarding services over the past five years.
It says the diocese could be used as an example to the rest of the Irish Catholic Church.
The audit said that all 14 concerns or allegations made since the appointment of Bishop Treanor to the diocese in June 2008 had been properly managed.
The diocese was singled out particularly for its guidance on whistle-blowing, which the reviewers said was something they had not encountered elsewhere.
In a statement following the publication of the report, Bishop Treanor welcomed the audit describing it as "encouraging".
He said his hope was that the work of the diocese's Safeguarding Office and volunteers ensure that the inadequate response of the past will become a thing of the past.
Armagh policy and procedures 'need to be clearer'
The review found that in the Diocese of Armagh, while the policy and procedures are comprehensive in setting out how to manage risks to children when they are initially uncovered and in the short to medium term, they are less clear in setting out how the church proposes to manage individuals in respect of whom there are longer term risks.
The report says reviewers saw no reference in the policy and procedures to a protocol for dealing with respondent priests or others against whom an allegation might have been made but where the civil processes have been discontinued.
It said the policy and procedures need to be clearer about the processes for internal investigation by the church and for the management of those who continue to present a risk to children.
The review found three assessment criteria had been partially met.
The review says there were 16 Diocesan priests in the Archdiocese of Armagh against whom allegations have been made since 1975 to the date of the review.
In their audit, reviewers say there were references to a total of 36 alleged victims of clerical sexual abuse during this time.
They say 36 allegations were reported to the relevant police services involving priests since 1975.
Of these 33 were reported to relevant social services.
The report says four priests against whom an allegation has been made, including complaints and expressions of concern, are in ministry.
Eight priests who were still members of the diocese or order against whom an allegation was made were still living at the date of the review. Seven priests against whom an allegation has been made have died.
Two priests against whom an allegation was made are still members of the diocese and are termed "out of ministry".
Two priests against whom an allegation was made are retired; one priest against whom an allegation was made had left the diocese or priesthood.
The review finds one priest had been convicted of having committed an offence, or offences, against a child or young person since 1 January 1975.
The audit states that all allegations made refer to the period between 1950 and 2000.
Of these 19 events are reported to have happened between 1950 and 1980 and 13 events between 1980 and 2000.
In four instances it states the dates of alleged abuse are not recorded.
It finds that there have been no new allegations that refer to abuse having been perpetrated after the year 2000.
Diocese of Kerry 'committed to child protection'
The audit of child protection practices in the Diocese of Kerry revealed that allegations of abuse had been made against 21 priests there over the past 37 years.
67 separate allegations were made against these priests and the audit found that all of these had been reported to gardaí and the Health Service Executive.
The audit said it is clear from its policy statements that the diocese is committed to child protection.
The audit found that allegations of child abuse have been made against a priest who was allowed provide holiday cover in Co Kerry when he retired to the diocese, despite having abused a large number of boys in the previous diocese where he served.
The audit states that authorities in the priest's old diocese were aware of allegations against him, but this information was not shared with the Bishop of Kerry.
In a statement, Bishop Ray Browne expressed his "sincere sorrow and regret" to anyone who had been abused by a priest in the diocese.
He fully accepted the findings and the recommendations of the review, and said the diocese will "continually strive to fully safeguard all children in our care".
Kiltegan Fathers' leadership 'challenged'
The audit into the Kiltegan Fathers (St Patrick's Missionary Society) acknowledged that the leadership of the society had been challenged by a relatively high incidence of serious and ongoing abuse among its members.
The review said the NBSCCCI would be aware of some of this abuse through other reviews already undertaken.
The review also stated that the society, which currently has its headquarters in Co Wicklow, is likely to move its base to Africa in the coming years.
The report cited the example of a Kiltegan Fathers priest in Kenya who it is believed may have abused at least 50 victims since 1966.
The audit found there were local reports which raised concern about homosexual activity between the priest and young Goan boys in the 1960s, however this information was not communicated to central leadership until 1997.
The man was stepped aside from ministry in 1986, and remained a member of the society until 2002.
To date, the society has made contact with 34 of the 50 people involved.
The audit found the priest was dismissed from the clerical state at his own request, which was the only way in which this could happen while the society was under the jurisdiction of the Congregation for the Propagation of the Faith.
In another example, a priest was accused in 2006 of abuse of a young person in Africa 26 years previously, and the priest admitted the allegation.
An assessment found he was at low risk of re-offending.
In 2012, a second allegation emerged leading to a second assessment, which identified several previous incidents of offences against young people by the priest when he was on mission in Africa.
The audit noted that because of the passage of time it was extremely difficult to identify child victims abroad who are now adult and who have not come forward themselves to make a complaint.
The audit recommended that the leadership of the society should ensure that all allegations of clerical abuse are responded to quickly in compliance with church requirements and in accordance with the standards of the society.
The report revealed a letter in which a society leader expressed regret to a member at the fact that he had decided to leave and seek laicisation, despite the fact that the priest was a self-confessed abuser of young boys while serving on the missions.
12 recommendations for Diocese of Ossory
The diocese caters for 85,000 people in the southeast and has 42 parishes in counties Kilkenny, Laois and Offaly.
The review of safeguarding practices from 1975 to 2012 found that during that period, allegations of abuse had been made against 14 priests from the diocese.
Two priests had been convicted of having committed an offence against a child or young person since 1975.
It found there are four priests still members of the diocese against whom an allegation was made and who were living at the time of the review, which was last year.
It also states there are three priests still in ministry against whom allegations have been made.
Regarding the meeting of criteria to safeguard children, the diocese has fully met 22 standards, partially met seven and not met three standards identified by the board.
One of the standards only partially met was the process for dealing with complaints made about unacceptable behaviour towards children.
The report also found that there was limited evidence of a pastoral response to victims of child abuse in the past.
The report has been welcomed by Monsignor Michael Ryan, Vicar General, Diocese of Ossory on behalf of Bishop Seamus Freeman, who is on sick leave.
Management of priests in Achonry 'problematic'
The report found that the issue on the management of priests in the Diocese of Achonry had been problematic.
In 1981, a priest brought in with the help of a religious order, and without the knowledge of the then bishop, went on to abuse a boy. He is currently serving a ten-year prison sentence for abusing 18 boys in five counties between the 1960s and the 1980s.
The reviewers found evidence that information about the priest's abuse of the young boy had been made available to another priest in the diocese at an early stage, but this had not been passed on by the diocese to the gardaí.
The report confirms there was further strong evidence brought to the attention of the diocese in 1997 on the same case but the complaint was not passed on to gardaí until 2002.
Bishop Brendan Kelly has already published an apology for the manner in which the diocese managed complaints against this priest.
Bishop Kelly today said he has spoken to his predecessor, Bishop Thomas Flynn, but has no explanation as to why evidence of allegations of assault by a serial sex abuser were not passed on to gardaí by the diocese for nearly 20 years.
Speaking in Ballaghadereen, Co Roscommon this afternoon, Bishop Kelly said he had discussed these questions with Bishop Flynn from time to time but all he could do at this particular time was to ensure that whatever mistakes were made in the past would not be repeated at the present time.
Former priest Peter Kennedy, who was extradited from Brazil and is now serving a ten-year jail sentence for abusing 18 boys in five counties, had worked for a period of time in the diocese of Achonry in the early 1980s when an allegation was made about his behaviour to a priest in the diocese at an early stage but was not passed on to gardaí until 2002.
Bishop Kelly also said he had informed gardaí of the presence of two retired priests who had not worked in ministry in the diocese but lived locally and were facing allegations of sexual abuse overseas.
He said he would act on a recommendation in the report of the National Board for Safeguarding Children in the Catholic Church today and contact the bishops of the religious orders responsible for the two men, but it was now the business of gardaí to carry out any further investigation that needed to be done.
Recommendations of Cashel & Emly review accepted
The Archbishop of Cashel and Emly has said he fully accepts the recommendations of the report into safeguarding children in his diocese.
Archbishop Dermot Clifford said he can assure the people of the diocese that the church will continue to do everything in its power to protect the children and young people involved in church activities.
He said most of the seven recommendations of the report have been implemented and the rest will be implemented as soon as possible.
The report found there were allegations of abuse against 13 priests in the diocese from 1975, seven of whom are still alive.
No priests were convicted of any of the offences alleged.
Fourth group of audit reports
It is the fourth group of audit reports from the National Board for Safeguarding Children in the Catholic Church.
Drawing on records in church files, they examined the response to allegations since 1975.
It also reported on current arrangements for safeguarding children.
In a statement today, Cardinal Seán Brady said with the co-operation of safeguarding personnel, he undertakes to "act promptly" on the recommendations in the audits.
Charity One in Four has welcomed the publication of the reviews saying "huge strides have been made in ensuring that children are safer than ever before from sexual harm".
However, the organisation said some serious concerns are identified in the reviews particularly in relation to the Christian Brothers and to the Kiltegan Fathers.
The finding that the response by the Christian Brothers to survivors was overly litigious and weak in pastoral care matches the experience of One in Four clients the charity said.
Regarding the Kiltegan Fathers, the charity said a major problem exists in that complaints of child sexual abuse made against priests working in developing countries have not been addressed.
The charity also expressed concern at the small numbers of alleged sex offenders who have been convicted in a criminal court.