The Ombudsman has launched an investigation into how complaints are handled by public hospitals.
Members of the public are being asked to share their experiences of making complaints or explain why they decided not to complain.
The investigation will involve visiting a sample number of hospitals and examining Health Service Executive files to see how complaints were dealt with.
Focus groups will also be held, along with interviews with front line and senior staff.
Announcing the investigation this morning, Ombudsman Peter Tyndall said: "Despite a high number of interactions with our hospitals, relatively few people complain when they are unhappy with the service they receive."
Mr Tyndall said in comparison with other jurisdictions, complaints to the HSE and to the Ombudsman office are very low and he wants to find out why.
He said in 2013 the Ombudsman office in Ireland received 130 complaints about health care, whereas in Wales, which has a smaller population, 682 complaints were received.
The public can share their experiences on ombudsman.gov.ie, by emailing email@example.com, by calling 1890-22-30-30 or by freepost Ombudsman,18 Lower Leeson Street, Freepost F5069, Dublin 2.
Speaking on RTÉ's News At One, Mr Tyndall said there were a number of reasons for the relatively low level of complaints his office receives about the health service.
In some cases, he said, people were simply not being told how to make a complaint and in others they were afraid that complaining could impact on their future treatment.
However, he stressed that complaints are a vital way of improving health services.
The Ombudsman said he hopes to publish his findings, conclusions and recommendations in early 2015.