The vast majority of koalas that wind up in the care of vets will die or have to be put down, often due to car strikes and dog attacks.
University of Queensland researchers have reviewed 22 years of data from wildlife clinics in the state's southeast, where koalas are endangered.
The findings say a lot about what's driving the species towards extinction.
Diseases, such as chlamydia, accounted for almost 30 per cent of admissions.
But that was matched by vehicle strikes and dog attacks, which together accounted for 27 per cent of admissions.
Crucially, survival rates were much worse for koalas that were hit by traffic or mauled.
In all, 75 per cent of the 33,290 koalas admitted over about 20 years died or were euthanased with just 25 per cent released.
PhD candidate Renae Charalambous says the findings show how important it is to minimise the risks of koalas interacting with traffic and dogs.
"It beautifully highlights two areas of concern that we should immediately focus on," she has told AAP.
"Koalas that were hit by cars were four times more likely to die than they were to be released. It shows you they don't have much of a chance once they have been hit."
The study also found adults, females and those with chlamydia were at higher risk of being euthanised than released.
Work is well advanced on a chlamydia vaccine for koalas, with a two-year pilot program under way in Brisbane.
In February 2022, the conservation status of the treasured marsupial was changed from vulnerable to endangered in Queensland, after estimates their numbers had halved over the past decade.
The analysis relied on data gathered by Australia Zoo Wildlife Hospital in the Sunshine Coast region, Currumbin Wildlife Hospital in the Gold Coast region, RSCPA Wildlife Hospital in Brisbane.
