Close supervision is the key to preventing the deaths of children under five in accidents involving cars, a new study has found.

A study of 37 transport-related deaths of young children in Queensland has found more than half were caused or contributed to, by inadequate supervision.

It was a common factor in 45 per cent of pedestrian deaths of the children.

The Commission for Children says in 78 per cent of those cases it involved failure to adequately supervise the child around a moving vehicle, a common risk factor for low-speed vehicle run-overs.

Acting Commissioner Barry Salmon says the tragedy is that all the deaths were preventable.

"It highlights the importance with really young kids of having comprehensive and on-the-ball supervision," he told AAP.

"You can't afford to be out of arm's reach, or take your eyes away from them when you have really young kids on the move, particularly around vehicles."

Mr Salmon says parents and carers have to look through the eyes of a child when they consider the risks from vehicles, even when they're moving slowly in a driveway.

"We keep a register of all the deaths of children in Queensland and the frustrating thing is that we're talking about preventable deaths here.

"It's just tragic."

New technology is helping to reduce the number of children killed by reversing vehicles, especially SUV's, he said.

"Manufacturers have responded fairly well and some of those vehicles with poor visibility now have reversing cameras, which is a great advantage and a positive move.

"But nothing beats close supervision and keeping young kids within arm's length."