The middle-aged man had no other major health conditions at the time of his death. Health officials have not released the man's name.
An elementary school-aged child with swine flu died May 29.
There have been at least eight deaths with /*H1N1*/ infection in California to date and at least 44 deaths around the United States.
In Contra Costa County there have been 120 confirmed and 109 probable H1N1 cases.