It is unclear whether high blood pressure per se or antihypertensive drug use causes erectile dysfunction (ED). The aim of this study was to investigate the effect of cardiovascular diseases and their concomitant medications use on the incidence of ED. The target population consisted of men aged 55, 65 or 75 years old residing in the study area in Finland in 1999. Questionnaires were mailed to 2837 men in 1999 and to 2510 of them 5 years later. The follow-up sample consisted of 1665 men (66% of those eligible) who responded to both baseline and follow-up questionnaires. Men free of moderate or severe ED at baseline (N=1000) were included in the study. ED was assessed by two questions on subject ability to achieve or maintain an erection sufficient for intercourse. Poisson regression model was used in the multivariable analyses. The risk of ED was higher in men suffering from treated hypertension or heart disease than in those with the untreated condition. The risk of ED was higher in men using calcium channel inhibitor (adjusted relative risk (RR)=1.6, 95% confidence interval (CI) 1.0-2.4), angiotensin II antagonist (RR=2.2, 95% CI 1.0-4.7), non-selective beta-blocker (RR=1.7, 95% CI 0.9-3.2) or diuretic (RR=1.3, CI 0.7-2.4) compared with non-users. ED was not associated with using organic nitrates, angiotensin-converting enzyme inhibitors, selective beta-blockers and serum lipid-lowering agents. In summary, calcium channel inhibitors, angiotensin II antagonists, non-selective beta-blockers and diuretics may increase the risk of ED.