New figures show that there were almost 107,000 adverse incidents reported in the health service last year and that the numbers have been rising each year over the past five years.
Adverse incidents can cover a wide range of events, such as slips, trips, falls, surgery on the wrong part of the body or patient, wrong medication, and patient injury and death.
More than 106,960 adverse incidents were recorded in the health service last year.
Just over 9% of incidents were classified as a near miss, while over 45% resulted in no injury.
Just under 10% of cases resulted in an injury requiring medical treatment.
There were 550 deaths associated with an adverse event last year.
The figures are for HSE hospitals and services, but do not include voluntary hospitals.
The HSE has said that an increase in the number of reports is unlikely to reflect an increase in the number of such incidents, but rather an improvement in reporting culture.
It added that very serious incidents are at less than 1% of all incidents and this is in line with international norms.
The HSE said that for the five years since 2018, the majority of incidents had no harm or low-level harm reported.
It said that all incidents are identified, reported and reviewed so that learning from events can be shared to improve the quality and safety of services.
Staff are encouraged to report all "near misses" and incidents, even those that do not result in harm.
The details were provided to Aontú leader Peadar Tóibín in a HSE response to a parliamentary question.
Mr Tóibín said the latest figures for last year represented a record and described as "jaw-dropping" that there were just under half a million adverse incidents in the past five years.
He said that nearly 500 people suffered an adverse incident that resulted in long-term or permanent disability and that over the five years, there had been more than 3,140 deaths.
Previous figures supplied to Mr Tóibín show that around €1.4bn in compensation has been paid out by the State Claims Agency for HSE adverse incidents in the last five years.
He said there was a need to drill down to identify the causes of these events.
In its response to the figures, the HSE said that the health service is treating significantly more patients.
For the most recently available 12 months of data, it said there were 3.5m outpatient and around 1.8m inpatient/day case attendances.
In addition to this, the HSE said the planned care hospital system also treated around 1.7m patients and in emergency care, there was an 11% increase on 2019 pre-pandemic levels.
