Researchers from the renowned Karolinska Institute in Sweden say on average, autistic adults died 16 years younger than members of the general population.
A STG10 million ($A19 million) research program will investigate why autistic adults are dying decades before their time.
The five-year project planned by the charity Autistica follows a bombshell study from Sweden that uncovered evidence of "shameful" premature death among people with the developmental disorder.
Researchers from the renowned Karolinska Institute analysed data on 27,000 people with autism and compared them with nearly three million non-autistic "controls".
They showed that, on average, autistic adults died 16 years younger than members of the general population. Those who also suffered from a learning disability died more than 30 years prematurely, at an average age of just 39.
Autistic people who were not held back intellectually died 12 years early, and even "high-functioning" individuals with good speech and language skills had double the normal risk of dying young.
"This new research confirms the true scale of the hidden mortality crisis in autism," Autistica's chief executive Jon Spiers said.
"The inequality in outcomes for autistic people shown in this data is shameful. We cannot accept a situation where many autistic people will never see their 40th birthday."
Autism is a lifelong disability that impairs a person's ability to communicate with and relate to other people.
As a "spectrum" condition, it impacts people in different ways and has symptoms that range from mild to very severe.
The Swedish study led by Dr Tatja Hirvikoski was published in the online edition of the British Journal of Psychiatry in November last year.
Epilepsy and suicide emerged as two leading causes of premature death among autistic people.