Almost 68,000 people were waiting for an appointment for an inpatient or day case treatment at the end of September.
That is according to new figures from the National Treatment Purchase Fund (NTPF), which show 568,769 patients were waiting for a first hospital outpatient consultation.
Meanwhile, more than 22,000 patients were waiting for an appointment for a Gastrointestinal Endoscopy.
The NTPF will receive an additional €25 million in funding in Budget 2020 which it says will help to improve hospital waiting times.
The Irish Hospital Consultants Association (IHCA) has said the numbers are "unacceptable".
"The decision to allocate an additional €25 million to the National Treatment Purchase Fund, which previous experience has shown, is a short-term measure which does not solve the long-term hospital access problems facing public patients," Dr Donal O’Hanlon, IHCA President said.
“The consultant recruitment and retention crisis, with one in five permanent consultant posts now unfilled, is the key factor in the long wait times patients face and must be addressed by Government.”
Responding to today's figures, Fianna Fáil Spokesperson on Health Stephen Donnelly said that the number of people waiting to see a consultant for the first time remained "almost static" last month.
"The number stands at nearly 570,000, and it fell by just 729, or one tenth of one percent," said Deputy Donnelly.
“At this rate, it would take 65 years to clear this list – and all that would mean is that people could see a consultant shortly after they were referred.
"The Government target was to bring the total number of people waiting down from 516,000 to 509,000 in 2019.
"Instead, nearly 570,000 are waiting – up more than 45,000 since January."