The incident happened shortly after 10 p.m. Friday on the 300 block of Cuesta Del Mar. Police found a man on the sidewalk with a gunshot wound to his upper body.
He was pronounced dead at the scene.
Witnesses told police a passenger got out of a black truck and started arguing with several people, including the victim.
During the argument, the suspect pulled out a gun and shot the victim.
The driver and the passenger took off in the truck. The victim was not identified.
The shooting marks the first homicide in the city of Oxnard in 2011.
If you have any information regarding this shooting, you're urged to contact Ventura County Crime Stoppers at (800) 222-TIPS.