With three effective and safe phosphodiesterase type 5 (PDE5) inhibitors, the clinician now has multiple choices in the treatment of patients who have erectile dysfunction of all severities and etiologies. Based on pharmacokinetics, pharmacodynamics, efficacy, and safety, each of these agents can be used. Because no well-controlled head-to-head selection or patient preference studies are available, each clinician must choose an agent based on the profile of the patient, his tolerance, risk factors, and side effects. This discussion summarizes some of the current data on PDE5 inhibitors and their efficacy, safety, and use in other conditions.