The cancer mortality experienced by a cohort of 1807 workers from a semiconductor factory during the period 1970-82 has been investigated (as has cancer morbidity for 1970-81). Expectations for mortality were calculated on the basis of rates of mortality for the general population of England and Wales. Expectations for cancer incidence were calculated on the basis of incidence rates for the West Midland Region. For the total study cohort, observed numbers of deaths and incident cases for all cancers were close to expectation. For melanoma incidence, an observed of 3 cases was compared with an expectation of 0.68.