An epidemiological study was conducted on bladder cancer in workers exposed to aromatic amines. The cohort consisted of 1,312 male workers of a factory that manufactured beta-naphthylamine (91598). Approximately 32 percent of the cohort were white, and 68 percent were non white. The employment files of workers were referred to for information on date of birth, medical history, number of years at job, employment date, and date of death. The observed and expected numbers of deaths by cause of death and race of worker were determined; the standard mortality ratios and 95 percent confidence interval were evaluated. There was a total of 262 deaths observed in comparison to 241 deaths expected based on United States mortality rates. The overall standard mortality ratio was 109 for all types of cancer; the standard mortality ratio was essentially the same for other causes such as tuberculosis, psychoneurotic disorders, circulatory disorders, digestive disorders, and non malignant respiratory diseases. However, mortality from cancer of all sites was significantly lower than expected, 34 deaths observed in comparison to 37.2 deaths expected. Two deaths were attributed to bladder cancer in relation to 0.7 deaths expected. The authors conclude that despite a small number of deaths, there is an excess risk of deaths due to bladder cancer in the beta-naphthylamine manufacturing facility.