Paid childcare costs rose 23 per cent in the two years to 2005 and now average €120 per week, according to data released by the Central Statistics Office today.
Parents in the Dublin region paid 24 per cent more for childcare last year at €145 a week compared with just under €100 for parents living in Border regions.
Families requiring more than 40 hours of childcare faced an average weekly bill of €185.
The size of the childcare sector was also revealed with the CSO saying 82,600 families (40.3 per cent) with pre-school children relying on non-parental childcare while at work.
This is up more than 2 per cent compared with 2002.
Pre-school childcare is more expensive at an average cost of €131.35 per week than childcare for primary school children which has an average cost of €86.82
The Dublin region has the highest hourly pre-school childcare rate of €5.15, which is 24 per cent higher than the national average.
Fewer families require childcare once their children reach primary school with 66,700 families (21.5 per cent) using this on a regular basis, which is slightly down on the figure for 2002.
According to the CSO couples (30 per cent) with pre-school children relied more on paid childcare than lone parents (18 per cent)
Unpaid relatives had a significant role in child care last year with almost one in ten families relying on a family member to look after their children.
There were also strong regional differences in the use of unpaid childcarers. While créches or Montessori schools were the most popular non-parental childcare providers in the Dublin region, in the Border, midlands and south east regions unpaid relatives was the mainstay of childcare.
The reports also found that under a third of lone parents with pre-school children were working, among couples more than half or 55.7 per cent of mothers or guardians were working.
Minister for Children Brian Lenihan said he was "concerned about the cost of childcare" as highlighted in the survey.
Mr Lenihan said the new Childcare Investment Programme will continue to create and increase the supply of places, one of the effects of which is to keep costs down.
The Government's package also provided direct assistance to parents to meet their childcare costs.
He said the National Childcare Investment Programme provides for "record investment" of €575 million over the next four years with a target of 50,000 new childcare places by 2010.
The package also included the Early Childcare Supplement, a non-taxable payment to all parents with children aged six or under of €1,000 a year to help parents meet their childcare costs, he added.
