The victim arrived at his NW 120th Street home just before 4 p.m. When he went inside, he was met by the trio of masked men, who police believe got into the house through a rear door.
The armed robbers tied up and threatened to kill the man before leaving on foot with his cash and various other personal items, police say.
The victim wasn't injured and was able to free himself and call 911 after the robbers left.
Officers canvassed the area but were unable to track down the home invaders.
There are no suspect descriptions available, but anyone with information about the robbery is asked to call 911 or the Seattle Police Robbery Unit at (206) 684-5535