The understanding of pharmacology of impotence has shown a steady improvement over the last 15 years which has resulted in a better appreciation of the neurovascular mechanisms of the erectile process especially at the level of the corpora cavernosa; however, central mechanisms which control libido and erection are not yet completely elucidated. Frequent diseases most commonly encountered in elderly patients--i.e. diabetes, hypertension, atherosclerosis, depression, etc--represent a frequent cause of erectile dysfunction (ED) and are treated with medications that can interfere with sexual functioning at the central and/or peripheral level. Antidepressants, including the tricyclics and the monoamine oxidase inhibitors, have been implicated in ED, decreased libido, and impaired ejaculation. Most antihypertensives have been associated with some erectile impairment, but diuretics seem to have little effect on erectile function. The calcium channel blockers and ACE inhibitors are associated with a low incidence of ED. Sympatholytic antihypertensives seldom cause importence but can cause retrograde ejaculation because of the relaxation of the smooth muscles in the prostatic urethra and bladder neck. The most commonly prescription drugs that can affect sexual function are briefly discussed and an integrated pharmacological approach to the patient with drug-induced ED is proposed.