The mortality experience of alcohol process workers (N = 1031) from two chemical plants was followed from the early 1940s to 1983. Reported associations of the production of ethanol and isopropanol by the strong-acid process with upper respiratory tract cancers, heart disease, and lympho- and reticulosarcoma were tested with both external and internal comparisons. Excesses of cancers of the larynx, buccal cavity, and pharynx, based on very small numbers, were observed. There was one death due to sinus cancer. It could not be concluded that there were work-related effects on mortality due to heart disease or lympho- or reticulosarcoma. Workers assigned to the production of isopropanol by the weak-acid method showed no evidence of excess cancer mortality (0 observed, 1.9 expected cancer deaths). The absence of major risks among strong-acid workers can be explained by the initiation of engineering controls and health monitoring that took place after the original medical observations.