The State Opposition, which obtained the data under freedom of information, believes the figures have revealed another crisis in Victoria's child protection system.

Barwon South West records show that 553 children were in out-of-home care to June 2009. Of those who had exited the system in 2008-09:

- 43 children had three or more placements while in out-of-home care

- 20 vulnerable children who had been in care for less than one year had three or more placements.

Opposition Community Services spokeswoman Mary Wooldridge said children who could no longer live safely in their own homes were being exposed to further trauma under the government's out-of-home care system.

"As (Community Services) minister, Lisa Neville has failed in her responsibility to ensure abused and neglected children have stability and a sense of safety in their lives," Ms Wooldridge said.

"In 2005, Ms Neville admitted that a sense of stability was vital for vulnerable children and said 'we need to move to a system that enables that child to have a stable environment.' "Five years on, out-of-home care in Victoria is in an appalling state and vulnerable children are suffering because of the Brumby government's inability to deliver real improvements."

Ms Neville said most children placed in out-of-home care were moved on two or fewer occasions.

"We want all children to be placed in stable environment; however, we will not hesitate to move a child if it is in their best interest," she said.

Premier John Brumby admitted the system was not perfect, but said the majority of the 5000 children in foster homes were well cared for.

"There's a small minority who betray the trust of the children in their care and as a government we have to put tighter checks in place to try and ensure that that won't happen," Mr Brumby told reporters.

"We are putting in more resources, but the system is not perfect." With AAP