Most parents would consider donating their own and their child's organs but have not put themselves on the official register. 

Parents are being urged to discuss organ donation with their children, as a poll shows just one in four have registered a decision about whether or not they want to be a donor.

Most parents (81 per cent) said they would be willing to donate their own organs if they died, and two-thirds (66 per cent) said they would consider donating their child's organs, research by the Royal Children's Hospital Melbourne for a national poll found.

Despite this, just 26 per cent have registered their decision with the Australian Organ Donor Registry, according to the poll.

A number of false beliefs around organ donation were also uncovered, showing that almost half (42 per cent) of parents believe toddlers and pre-schoolers who have died are too young to donate organs, and 40 per cent have concerns that a parent would not be able to spend time with their child after they have died if they donated their organs.

While reasons for parents not discussing organ donation with their children included fears it would be too upsetting and not knowing how to start the discussion, most (52 per cent) said they had just not really thought about it.

Dr Anthea Rhodes, director of the RCH poll, said people should register their decision, whether it is yes or no, so their families can have certainty around their wishes.

"Having a conversation about organ donation with your partner and children can be a difficult chat for a parent to have, however it is one of the best ways to for family members to understand each other's wishes on organ donation," she said.

Dr Rhodes also reminded people that South Australia is the only state where organ donor decisions can be registered via a driver's licence, after the poll showed that 55 per cent of parents still believe they could register in this way no matter what part of the country they were in.

* The Royal Children's Hospital National Child Health Poll surveyed 1886 parents who care for 3251 children aged between one month and 18 years old. People can register at donatelife.gov.au.