A dynamic retrospective cohort study was performed to examine the mortality experience of workers at Exxon's Baton Rouge, La refinery an chemical plant. Included were 8,666 regular employees who worked at least one month during the period Jan 1, 1970 through Dec 31, 1977, and retirees who were alive as of Jan 1, 1970. Mortality from all causes of death was lower than expected when compared with that of the U.S. population of similar age, sex, and race. Analyses of mortality by specific site of cancer revealed elevated standardized mortality ratios SMRs) for cancer of the kidney, testis, brain/central nervous system, pancreas, and lymphopoietic sites; none of these elevations was statistically significant. Because of the higher than average mortality from cancer of the pancreas in some Louisiana parishes and the observation that one additional death from cancer of the pancreas in this study would have resulted in a statistically significant SMR at the 95% confidence level, some emphasis was placed on this finding. No evidence was found to link cancer of the pancreas to a specific occupational group. An examination of mortality by occupational class revealed some elevated SMRs for further study.