Qantas's modest profit shows the carbon tax's hit on aviation and tourism, opposition environment spokesman Greg Hunt says.
Mr Hunt says the airline's net profit of $5 million for 2012/13 would have been far greater had it not had to pay its carbon tax bill of $106 million.
He says the company's bill for income tax was 10 times less at $11 million.
"It is a real impost on one of Australia's great companies," he told reporters at Hobart airport.
"The numbers are evident for everybody."
The coalition has pledged to abolish the tax in the first sitting of parliament after the election if it wins government.
Mr Hunt said the tax was hitting tourism hard and not reducing Australia's emissions.
Qantas's profit was up from a $245 million loss in the previous year.