OBJECTIVE This study compared survival after diagnosis of prostate cancer (PC) in men previously treated with finasteride, in men previously treated with α-adrenoceptor antagonists, in men treated with both, and in men who had received neither type of medication. MATERIAL AND METHODS In total, 3791 men diagnosed with PC in northern Denmark were identified. The region's prescription database was used to identify all men prescribed finasteride and α-adrenoceptor antagonists and those who had received neither medication during the period 1989-2001. Among men with a diagnosis of PC, overall survival and disease-specific survival were assessed after diagnosis using Cox proportional hazards regression. The risk of being diagnosed with non-localized PC was estimated using conditional logistic regression. RESULTS The adjusted hazard ratio (HR) for PC death and overall death after treatment with finasteride was 0.93 [95% confidence interval (CI) 0.76-1.14] and 0.92 (95% CI 0.77-1.10), respectively. Treatment with α-adrenoceptor antagonists was associated with a reduced risk of PC death and overall death (HR 0.78, 95% CI 0.67-0.90, and 0.82, 95% CI 0.73-0.93, respectively. The risk of being diagnosed with non-localized PC was increased for men taking finasteride (odds ratio 1.14, 95% CI 1.01-1.29) per 100 defined daily doses. CONCLUSIONS Treatment with finasteride prior to a diagnosis of PC did not affect PC-specific survival, but increased the risk of being diagnosed with non-localized disease. Treatment with α-adrenoceptor antagonists was associated with better cause-specific survival and lower risk of non-localized disease.