Early studies of peak heart rates and blood pressure during coitus led physicians to believe that sexual activity represents a significant risk to patients with cardiovascular disease. Subsequent studies indicated, however, that the heart rate during coitus was no higher than the rate during unaccustomed physical exercise or associated with anger. The absolute risk of myocardial infarction (MI) in a patient with a history of MI has been found to be 10 per million per hour, and the doubling of this risk in the 2 hours following coitus has a negligible impact on annual risk. Coronary artery disease (CAD) is a powerful indicator of the presence of erectile dysfunction (ED), and the risk factors for ED are similar to those for CAD. Studies of sildenafil citrate use in patients with a history of cardiovascular disease have found sildenafil to be safe and effective, except for an absolute contraindication in the concomitant use of nitrates. Physicians should become familiar with the clinical guidelines for classifying ED patients with a history of cardiovascular disease as high risk, intermediate or indeterminate risk, and low risk. The guidelines permit physicians MIlow risk while deferring the resumption of sexual activity among higher risk patients pending further evaluation.