The Road Safety Authority has said it is concerned and disappointed at the low level of drink-driving convictions.
New figures published today show that only 40% of drink-driving cases listed before the country's district courts since January 2013 resulted in convictions.
Between January 2013 and May 2015 more than 20,000 people were due before district courts for drink driving, yet just over 6,700 or 40% were convicted.
Co Kerry had the lowest conviction rate at 29%.
The highest conviction rate was in Co Offaly at 68%.
The RSA said it is a matter for the Department of Justice and the courts.
The figures from the Department of Justice were supplied to Road Safety campaign group PARC, through a parliamentary question tabled by Independent TD Tommy Broughan.
A former state solicitor has said he is not surprised at the low rate of convictions.
Ciaran MacLochlainn, who is now a defence solicitor having previously been state solicitor for Donegal, said a number of factors are in play during a prosecution.
Speaking to RTÉ's News at One, he said there are a lot of technicalities in drink-driving law and there is plenty of room for challenge.
Mr MacLochlainn compared a drink-driving case to a hurdle race, saying "there are about ten hurdles to get over and if a guard hits any of the hurdles the case will collapse".
"If, as invariably happens, you have a young inexperienced guard giving evidence he can sometimes hit a hurdle and down will go the case," he said.
Mr MacLochlainn said the consequences for someone convicted of drink-driving were severe and that made them willing to challenge prosecutions.
When asked about the difference in conviction rates between the UK and Ireland, he said he could not speak for the UK but that he has found lawyers in Northern Ireland are less likely to challenge drink-driving prosecutions.
A spokesperson for Minister for Justice Frances Fitzgerald said this evening that she is committed to ensuring that road traffic offenders who are prosecuted are convicted where warranted.
The spokesperson said the minister has asked the department to review the figures supplied by the courts service.
