The service was alerted at around 5am on Monday to the fire in Scotland Street in the city’s southside.
The one-storey garage is alight and a number of cars are on fire.
Firefighters are also cooling down two gas cylinders as a precaution and a number of other cylinders on site are as yet unidentified.
A spokesman for the Scottish Fire and Rescue Service said: “Around 50 to 55 firefighters are in attendance.
“The one-storey building has a garage on the ground floor and an unknown quantity of cars are on fire.
“There are also a large quantity of unidentified cylinders involved.”
Nearby streets Carnoustie Street and Shields Road have been closed to traffic.