A new survey has found that one in 10 parents are not bothering to put their children in car seats.

Seventeen infants were killed and hundreds more injured in car accidents last year and experts say many of those deaths and injuries should have been prevented.

The survey found 546 babies and children were injured in 2005 in car crashes and one in 10 of our children aren't restrained in cars.

Plunket Society president Kaye Crowther says they are concerned about the results.

"Children have been killed because they haven't been restrained and that is always a concern, but we just have to keep promoting and keep giving those safety messages," she says.

Age and size determines how a child is belted up.

Child restraint expert Jocelyn Pedder says one of the biggest issues is people transferring children into car seats prematurely out of the restraint that is correct for their weight.

"If you put them forward facing too soon they could actually sustain fatal spinal injuries, bad head injuries and with the same if you put a child in a seatbelt too soon, again it could be spinal injuries or it could even be abdominal injuries," says Pedder.

She says it is far safer to have a child rear facing for as long as possible. In New Zealand the current advice is to keep children rear facing until at least one year old.

"If you assume that the majority of the big crashes are going to be head on... then if you put the child, or baby, forward facing too soon, their neck, their whole development is not yet advanced enough and you get literally stretching of their neck and the child can sustain fatal or very, very serious spinal or neck injuries," Pedder says.

A safety forum in Wellington this week aims to address some of the issues that result in children dying in car accidents.