The data in the literature on the relationship between sexual activity, with and without the use of sildenafil, and the occurrence of cardiovascular events (ventricular arrhythmias, nonfatal myocardial infarction, stroke and death) have been reviewed in patients with heart disease. To date, only patients with ischemic heart disease (IHD) have been investigated. The prevalence of premature ventricular beats during sexual intercourse is similar to that observed during other daily activities. Therefore, sexual activity does not seem to have a relevant arrhythmogenic effect. The incidence of sustained ventricular tachycardia during sexual intercourse in unknown. The relative risk of nonfatal myocardial infarction is 2.7 in males and 1.3 in females; however, the absolute risk appears extremely low and is similar in normal subjects and in patients with and without IHD. The risk appears to be restricted to the 2-hour time period after sexual intercourse. The incidence of stroke during sexual intercourse appears very low, but clear data are lacking. The incidence of death during sexual activity is unknown; the few available data suggest that it is very low. Extramarital sexual intercourse seems to increase the risk of death. The incidence of cardiovascular events after sildenafil administration has been investigated in placebo-controlled studies in patients with IHD. The incidence of nonfatal myocardial infarction, stroke and death did not significantly differ between sildenafil-treated and placebo-treated patients; therefore, sildenafil does not appear contraindicated in subjects with IHD. However, the drug should be administered with caution in patients with recent myocardial infarction or stroke, in those with active coronary ischemia and in patients with episodes of heart failure. The drug is absolutely contraindicated in patients using nitrates.