There are more than 41,000 patients on hospital waiting lists for treatment at 32 Irish hospitals, according to new figures obtained by RTÉ News.
The number of patients waiting for day care treatment is 24,147, while 17,252 are waiting for an inpatient procedure.
The hospitals with the longest waiting lists are St Vincent's and Beaumont in Dublin and University College Hospital in Galway.
The waiting lists for inpatient and day care at these hospital are: St Vincent's 3,190, at Beaumont 2,497 and at University College Hospital Galway the figure is 2,533.
The region with the longest lists is the western HSE region, which has nearly 8,000 patients waiting for inpatient or day care treatment.
The government's national health strategy promised that by the end of 2003 no adult would wait longer than six months and no child would wait longer than three month for treatment.
The latest figures show that nearly 12,000 adults are waiting six months or more and over 2,200 children are waiting three months or more for treatment.
The figures come as the HSE has announced that its staff recruitment freeze will continue for at least another four weeks and several hospitals are under pressure to reduce their overspending.
The Taoiseach has told the Dáil that he is not sure where figures for hospital waiting times reported by RTÉ News came from, so he could not comment on them.
But Mr Ahern said that if the figure of 41,000 people on waiting lists was correct, it was a small percentage of the procedures carried out in the health service.
But, he said, that people waiting this long should be contacting the National Treatment Purchase Fund.
He was responding to Labour leader Eamon Gilmore, who pointed out that the HSE had introduced a recruitment ban in order to claw back overspending, and that this represented health cuts.
Mr Gilmore said the Taoiseach's response showed a very poor understanding of what people have to endure on waiting lists.
Mr Ahern said he understood the anxiety felt by people on waiting lists, but that the HSE was in receipt of €15bn this year, and had to stay within its budget.