Men with cardiovascular disease (CVD) are more likely to have erectile dysfunction (ED) than the general population, as both conditions share risk factors and some drugs used to treat CVD may induce ED as a side-effect. This study was undertaken to assess the efficacy and safety of sildenafil citrate for the treatment of ED in men with CVD who were receiving treatment with beta-blockers and/or angiotensin-converting enzyme inhibitors and/or calcium-channel blockers, but not nitrates. Treatment with sildenafil was associated with significant increases in the mean end-of-treatment scores for the questions from the International Index of Erectile Function that assess the ability to achieve and maintain erections (p = 0.0001). Furthermore, 71% of patients taking sildenafil reported improved erections compared with 24% taking placebo (p = 0.0001). This study also showed that sildenafil was well tolerated in patients with CVD and ED. Besides flushing, no treatment-related cardiovascular adverse events were noted for sildenafil.