The incidence and mortality of prostate cancer from 1957 to 1991 were studied in the Cancer Registry of Norway. The age-adjusted incidence rate increased from 26.3 to 46.6 per 100,000 person-years during the period, and more than 2000 cases are now registered yearly. The increase tends to be higher in the younger age groups, 50-59 years, and among the oldest, 90+ years. An increase was also found in cause-specific mortality, signifying a real increase in incidence over time. There is a slight urban dominance in incidence of prostate cancer. Autopsy findings account for less than 1.7% of the total. The histo- and cytological verification rate reached 94% in 1987-1991 and the percentage of localised cases was 68.4%. The median age at diagnosis in 1987-1991 was 75.1 years. Data on stage at time of diagnosis, histological differentiation and survival, reflect a small influence of earlier diagnosis. Model analysis revealed no particular birth cohort effect, either on incidence or on mortality.