Firefighters have spent the equivalent of nearly a day and a half handling call-outs at the old Strathmartine Hospital in the past five years.
The latest blaze was just last week at the derelict site, which closed in 2003 and regularly draws vandals and fireraising incidents.
A total of 31 hours have been spent battling blazes and there have been many more false alarms.
Firefighters were called out 60 times in the past five years to the site on the outskirts of Dundee.
The figures include 20 deliberate fires, two accidental blazes and 38 false alarms.
The fires cost crews 31 hours and 35 minutes.
Kirstene Hair, Scottish Conservative MP for Angus, said: “We need to see much faster progress in redeveloping the site so that the senseless vandalism there stops.”
Monifieth and Sidlaw Liberal Democrat councillor Ben Lawrie slammed the needless drain on resources.
“Deliberate fire-starting at Strathmartine Hospital has been a persistent problem over the years,” he said.
“I would encourage parents to make sure they know where their kids are.
“This kind of behaviour is a drain on the time of our fire service.”
Gordon Pryde, local senior officer for Dundee, Angus, Perth and Kinross, said: “For some, these structures can appear to be an area for adventurous play, however, the danger of harm is very real.
“There are a number of multi-agency educational initiatives already under way in an effort to educate communities on the dangers of deliberate fire-setting.
“There is no doubt that the actions of those who set deliberate fires can have a significant impact on the work of firefighters.”