A million people are on waiting lists for acute hospital appointments, according to the Irish Hospital Consultants' Association.
They also say 20% of consultant posts are vacant due to issues over pay and retention.
The IHCA national conference has heard that countries with similar population numbers have twice the amount of consultant staff.
It says projects such as the National Children's Hospital and a new urology initiative will be impacted by a shortage of staff and beds.
Addressing the conference this morning IHCA President Dr Donal O’Hanlon said nearly 570,000 are waiting to be seen by a hospital consultant.
He said the problem is getting worse with around 7,000 added to the lists each month this year.
The conference heard that the issues facing the health service can only be resolved if the ongoing difficulties recruiting and retaining hospital consultants is addressed.
With one-in-five consultant jobs now vacant the IHCA said the Government must start negotiations aimed at restoring pay parity for newer hires.
It said the staffing crisis is also set to have a serious impact on six key government health projects - the National Children's Hospital, the National Cancer Care Programme, the National Maternity Strategy the National Mental Health plan and major initiatives in urology.
IHCA Vice President Gabrielle Colleran said the health service can’t provide proper care with the number of consultants on the books.
“I will give you the example of neurology – where we launched a new national strategy earlier this month,” she said.
“We have only 37 neurologists in Ireland. That is a third of what they have per capita in New Zealand and only 15% of what they have in Denmark.
“So we can’t expect to be providing timely access to high-quality care when we just don’t have enough people in posts.”
The Health Minister Simon Harris was due to deliver the keynote address and debate opposition politicians at the meeting this afternoon; however, organisers said he cancelled at the last minute.
The minister cited a scheduling conflict in cancelling the appearance.
Later this afternoon, the consultants will hear research on burnout and stress among their colleagues and the stark contrast between working conditions here and overseas.
