Abbotsford Fire Rescue Service was called out to the Pizza Hut on South Fraser Way on Thursday night, shortly after 10 p.m.
When crews arrived they found heavy smoke coming from the roof and sides of the building.
Quick action by firefighters prevented the blaze from spreading.
Reports indicate the cause of the fire was a mop.
"In one of the back utilities rooms there was an old mop that was sitting up against the boiler that had heated up and caught on fire causing a little bit of fire damage and a little bit of smoke damage," said Jeff Adams, assistant fire chief.
He said damage was minimal, but charring occurred on some of the wood and a clean up will be needed.
Fire officials want to remind business owners to keep a clear area around boilers and make sure cleaning supplies are stored away from heat sources.