The Woodbine racetrack and casino were evacuated overnight after a man walked into the building and threatened to harm himself and others.
Police rushed to the Woodbine Entertainment centre in Rexdale just after midnight Wednesday. By that time, security had already placed the 32-year-old suspect in custody.
Authorities worked through the night with the Toronto police bomb squad to make sure the building was safe.
Police say the casino and racetrack were thoroughly searched as was the man's vehicle which was parked at the Woodbine shopping mall across the street.
Roads in the area were reopened by 8 a.m. when police cleared the scene.