The shooting occurred around 7 p.m. in the 900 block of Peach Avenue, east of Mollison Avenue.
The man, in his 40s, was transported to a Sharp Memorial hospital where he later died of from his injuries, according to El Cajon police. A witness said the man was shot in his side and in his chest.
The shooter was described as a heavyset man in dark clothing and was last seen running from the scene. Police were investigating to determine a motive for the shooting.
Anyone with information is asked to call police.