Cancer incidence was analysed in a retrospective cohort of 3710 male Swedish smelter workers between 1958 and 1982 using a record linkage with the Swedish Cancer Register. During this period 467 cancers were registered in the cohort. An excess incidence of total cancer of about 30% was shown relative to general and local populations mainly due to 120 respiratory cancers. Excess SMRs for all cancer and respiratory cancer were highly significant. Trends in the incidence of cancer were studied using moving five year calendar periods. A decreasing rate of lung cancer was found during 1976-80 for both mortality and incidence. Incidence figures for two more years show a continued decreasing trend. This is validated by an analysis of different employment cohorts, taking latency into account, showing that the later the date of first employment the lower the incidence of cancer, especially for lung cancer.