Brett Vollus, 52, worked for Qantas for 27 years as a flight attendant until his early-onset Parkinson's forced him to take redundancy in May this year.
Vollus engaged a specialist lawyer, Tanya Segelov, to look into his case after the Sydney neurosurgeon who made his diagnosis told him he was seeing "a lot" of cabin crew.
"He has no family history of Parkinson's and he believes the Parkinson's has been caused by his exposure to the insecticide that he sprayed as a long-haul flight attendant on at least a fortnightly basis over a period of 17 years when working on board aircraft," Segelov told AFP.
"There is a link in the medical literature between Parkinson's and other motor neurone disease and insecticide and that link is well established," she added.
Comment is being sought by AFP from the Australian government on the case, which is set to be filed next year in the New South Wales Supreme Court.
Segelov won an engine fumes suit in 2010 against East-West Airlines, a regional carrier of now-defunct Ansett Australia, on behalf of a flight attendant who suffered respiratory damage. She said Vollus's case could have national or even global implications.
"This is not an issue confined to Australia, and there are still countries that mandate this spraying as well," she said.
"Some Asian countries still do it, India definitely still does."
The spraying was mandated by the Australian government on World Health Organisation guidelines to prevent the spread of insect-borne diseases like malaria.
The issue raised questions over what the government knew of the potential risks to cabin crew or what is should have known, she added.
Segelov said practices had since evolved to allow spraying to take place once the aircraft was empty, in a hangar, and for the personnel carrying it out to wear protective gear.
"As I understand it from looking at the World Health Organisation requirements that option has always been available, so it would be interesting to know why it was mandated to be sprayed the way that it was," she said.
"From the research I've done I think (the Australian government) were the ones that made the decision to spray on board the planes and they did it in such a way with no protection was offered to my client -- he had a can in each hand, he couldn't even cover his mouth."