Children are being diagnosed with autism before their second birthday in a breakthrough trial that promises to save countless dollars and family heartache.

Using the expertise of child-health nurses to identify crucial developmental delays, the Melbourne study has significantly brought down the age at which children are first assessed for autism.

The researchers want the program to be expanded immediately, saying the developmental, financial and emotional benefits of early intervention are enormous for the children, their families and the community.

The study's leader, Cheryl Dissanayake, who heads the Olga Tennison Autism Research Centre at La Trobe University, said the program was a relatively cheap and effective way of identifying signs of autistic behaviour through the routine infant check-ups by maternal and child health nurses.

Nurses at 184 centres checked the children at eight, 12, 18 and 24 months. They were trained to look out for symptoms including a lack of eye contact or response to their names, or failure to point, wave or clap.

"These kinds of behaviours ... are evident from very early in development," Dr Dissanayake said. "They are focusing on children before they develop language and traditionally it's the failure to develop language that led children into the referral process."

Of 105 children referred for further testing by La Trobe University experts over the two-year study, 80 per cent had autism spectrum disorder and the remainder had language or developmental delays. Only one child - an extremely shy toddler - was incorrectly referred.

The early diagnosis - usually autism is not diagnosed until children are at least three - allows parents to enter specialised intervention programs before the disorder becomes more severe and secondary symptoms, such as aggressive behaviour, develop. But the program's funding, through a Telstra community development grant, runs out next month.

"We are over the moon - it's beyond our wildest dreams," Dr Dissanayake said about the success rate. "What we would like to do in the first instance is have the Victorian Government extend this across the state, and then I would like to see it spread much more across the nation."

Yvonne Hocking's son Mitchell was referred to Dr Dissanayake after a nurse at his two-year check-up noticed how he did not wave to her and changed activities erratically.

Ms Hocking had harboured concerns about her son's development since he was about six months old, but thought his unusual progress was due to his premature birth.

After the diagnosis of high-functioning autism, a year of speech therapy has expanded Mitchell's vocabulary from nothing to 100 words, his motor skills have developed dramatically and he is enrolled in a specialist service for autistic children that also teaches parents how to cope.

Ms Hocking helps her son, now aged 3½, by preparing "social stories" using photographs of him engaged in daily activities, such as going to the toilet, shopping or playing, to "pre-program his brain with what's meant to happen".

"When he was first diagnosed, I thought I won't have those special moments with my child ... but he comes up and tells me he loves me, he laughs, he cuddles me and kisses," Ms Hocking said. "I can't believe where we have come in a year."