Police responded to reports of a disturbance near 535 Buena Vista Ave. at about 11:50 a.m., Alameda police Lt. Sean Lynch said.
Arriving officers found a man suffering from gunshot wounds in the hallway of an apartment complex, police Lt. Ted Horlbeck said.
The man was pronounced dead at the scene.
The victim's name hasn't been released, but Horlbeck said he is a 32-year-old Oakland man.
The three men arrested are a 26-year-old Hercules resident, a 22-year-old Alameda resident, and a 22-year-old Laytonville resident. Police have not released their names.
Police are still investigating a motive but do not believe the shooting was gang-related.