The occupational and mortality patterns of about 200,000 White male residents of California during 1959 to 1961 were analyzed. Observed and expected cause specific death rates in a given occupation group were compared. Observed death rates were also compared with those from Washington State, England, and Wales. Mortality statistics were derived from death certificates of workers in 125 occupational categories. The statistics include such information as average age at death, average years worked, and specific cause of death. Within each occupational group, excess death rates from specific causes were identified. In general, the findings agreed with those of earlier occupational mortality studies. The authors conclude that occupation can be useful in explaining and interpreting mortality trends, but other factors, such as social and behavioral patterns, may also be significant.