Fire Rescue Victoria recorded a $170 million loss and failed to meet response time benchmarks last financial year.
The service's annual report for 2022/23 was tabled in parliament on Thursday, revealing the massive financial strain.
The $170 million loss came on the back of a $132.5 million loss the year before.
Its income grew to $961 million, but expenses now sit at $1.13 billion.
The report also shows crews did not always get to structure fires within the benchmark of seven minutes and 42 seconds.
The target was met 84 per cent of the time, down from 88 per cent the year before.
It's response times to medical incidents faired better.
Crews reached those in need within the nine minutes and 12 seconds benchmark 93.3 per cent of the time, slightly down on the 93.8 per cent in 2022.
Questions also remain over the December 2022 cyberattack.
The hack significantly affected Fire Rescue Victoria's technology and communications systems and exposed sensitive information.
Many of its internal systems became inaccessible and it affected even getting data for the annual report.
The organisation has since been told information might have been stolen and put on the dark web.
But as on June 30 the files purporting to be from Fire Rescue Victoria could not be verified to be containing any such data.
"We remain unsure whether the malicious third party is in possession of stolen data," the report says.
Some employee payments were delayed by months due to the need to make manual payments after the hack.
