Victorian Premier Denis Napthine says he understands most of the Qantas job losses will be in other states.
Dr Napthine also said he believes the 5000 positions being axed include those at Avalon, which have already been announced.
He is still seeking information about the geographic breakdown of the job losses to assess the impact on Victoria, where about 5700 people are employed by Qantas and Jetstar.
"We are working with Qantas to work out the impact on Victoria," Dr Napthine told reporters.
Three hundred workers will lose their jobs when Qantas closes its heavy maintenance base at Avalon near Geelong at the end of March.
A review found there was not enough work to keep the base viable for the company's soon-to-be-retired fleet of Boeing 747s.
Australian Services Union state secretary Ingrid Stitt said she was very concerned about anyone losing their job in Victoria given the current climate.
"There are thousands of people employed in Victoria by Qantas and Jetstar and across the Qantas group," she told reporters at Melbourne Airport.
"It is going to be really important that we fight for every one of those jobs in the current economic climate."
Opposition Leader Daniel Andrews said the Victorian government should have lobbied harder to save the jobs.
"This is a tragedy," he told reporters at Melbourne Airport.
"We as a state used to lead the way. Now I think we have slipped so far behind and Victorians deserve better than a premier that is a bystander, a premier that refuses to lay down a plan for jobs."
Mr Andrews said government cuts to TAFE would make it harder for sacked Qantas workers to find a new job.
