Police were called to an apartment in Scarborough, early Friday morning, where they found the body of a man lying on the balcony.
Det. Sgt. Frank Skubic said there were signs of trauma to the body and police had determined it is a homicide.
There were at least four people in the apartment on Greencrest Circuit, near Markham Road and Lawrence Avenue East, at the time.
Police received a call at about 2:30 a.m. about a disturbance, after neighbours heard a woman screaming inside the second floor apartment.
One woman was taken away by police.
Investigators say the occupants of the apartment speak Cantonese.
Police have not released any names.