Officers responded to reports of an assault in progress in the area of Munich and Cordova streets, according to police spokesman Sgt. Wilfred Williams.
Officers found a man who had been badly beaten sitting in the driver's seat of a vehicle, Williams said. The victim was transported to a hospital and pronounced dead at about 10:45 p.m.
Investigators canvassed the area and conducted interviews immediately after finding the man, Williams said. There are no suspects at this time, although Williams said the assault did not appear to be gang-related.
The medical examiner will determine the specific cause of death, but Williams said weapons did not appear to be involved.
Anyone with information on this incident is encouraged to call the San Francisco Police Department's anonymous tip line at (415) 575-4444.