About one in six children who needed a child care place in 2011 couldn't access it, government data released on Thursday shows.
The 2013 Report on Government Services also found that more than half of children whose parents worked and who needed to access child care to enable them to work weren't able to do so.
But this represented just 1.4% of all children aged under 12.
Government spending on child care and preschool services increased to $6 billion in 2011-12.
This worked out at $4,888 per child using the services.
Less than one-third of all children under 12 in Australian used child care in 2011-12.
But this proportion increased for toddlers, with 44.5% kids under five going to child care.
Disadvantaged children - including those from non-English speaking or low income families and Indigenous kids - were less likely to attend child care.
Children spent an average of 27.3 hours a week in long day care, at a cost of $341 a week. Long day care was the cheapest in Queensland and the most expensive in the ACT. Those in family day care spent an average of 22.2 hours a week in care, costing $323. The cheapest average cost was in South Australia and the most expensive again the ACT.