With the increase in detection at an early stage, only a few and conflicting results have been reported on the long-term outcome for prostate cancer beyond 10 years. The vast majority of prostate cancer patients diagnosed between 1955 and 1984 in southeastern Netherlands, with a population of almost one million inhabitants, did not receive any curative treatment. We calculated the prognosis for 10-year survivors of prostate cancer diagnosed in the era preceding prostate-specific antigen (PSA) testing to determine how long these patients exhibited excess mortality. All patients under age 70 diagnosed with prostate cancer and registered in the population-based Eindhoven Cancer Registry between 1955 and 1984 were included in the study. Relative survival was calculated for those who survived for at least 10 years (n = 174). Initially, these patients still exhibited an almost 25% excess mortality risk, but this decreased with time and no excess mortality was found after 15 years.