The results presented here are from the follow-up of the cohort of workers ever employed at the Springfields site of British Nuclear Fuels plc (BNFL) between 1946 and 1995. The main activity of the site is uranium fuel fabrication and uranium hexafluoride production. The study cohort consists of 19454 current and former employees, 13 960 of which were classified as radiation workers, and contains 479146 person-years of follow-up. The mean follow-up period is 24.6 years. To the end of 1995 there have been 4832 deaths recorded for this cohort, 3476 of which were amongst radiation workers and 1356 were amongst non-radiation workers. The standardised mortality ratios (SMRs) for all causes were 84 and 98 for radiation workers and non-radiation workers respectively. For all cancers the SMRs were 86 and 96 respectively. For cancer morbidity the standardised registration ratios (SRRs) for all cancers were 81 and 81 respectively. Significant associations were noted for both mortality and morbidity due to Hodgkin's disease and cumulative external dose. A strong association was also noted for morbidity, but not mortality, due to non-Hodgkin's lymphoma. These associations, however, are unlikely to be causal. The excess relative risk estimates for cancer other than leukaemia and for leukaemia excluding chronic lymphatic leukaemia are consistent with other occupationally exposed cohorts and estimates from the high-dose studies.