The Texaco mortality study is a retrospective follow-up study of all persons who were employed for at least five years in a refining, petrochemical, or research facility and who worked at some time during the period 1947 through 1977. Of the 19,077 white men in the cohort, 14,609 were alive, 4,024 were known to be dead, and the vital status of the remaining 444 was unknown as of Dec. 31, 1977. The standardized mortality ratio (SMR) of 75 for all causes was significantly low, on the basis of 5,332 expected deaths. Statistically significant deficits also were seen for all major causes of death and for cancer of many sites, including lung, stomach, bladder, and colon. The SMR was greater than 100 for six causes of death: pancreas cancer, brain cancer, leukemia, Hodgkin's disease, other lymphatic cancer, and benign neoplasms. However, none of these increases was statistically significant, and all SMRs except that for benign neoplasms (SMR = 148) were under 119.