While about 43% of people with drivers licences are registered as donors, hundreds of people remain on waiting lists for livers, lungs, hearts and kidneys.
National Organ Donor co-ordinator Janice Langlands says there has been a trend over the past ten to 15 years of donor ages increasing.
She says part of that is because of the falling number of people dying in road accidents.
Langlands says per million of population New Zealand's donor numbers are less than most countries, apart from Australia.
An organ donation lobby group says many doctors are not respecting the rights of registered donors.
Andy Tookey from the group Give Life New Zealand says with more than 40% of drivers registered as donors, there should not be such a shortage.
Tookey says many doctors are going against potential donors wishes and instead doing what the family wants.
He says he regards that kind of attitude from doctors as arrogant.
Meanwhile, the father of a seriously ill toddler in Auckland's Starship Hospital is still waiting to hear whether he can donate part of his liver to his son in order to save his life.
Eighteen month old Ethan Moore has a liver infection that is threatening his life and is in desperate need of a liver transplant.
Ethan's father Stuart says he hasn't got any options left.
"There's a left and right lobe in your liver and he gets quarter of that. This'll grow with him just normally, as normal as any kids will and mine'll grow back in six to eight weeks," says Stuart Moore.
