The advent of the first effective oral agent in the management of erectile dysfunction, sildenafil (Viagra; Pfizer US Pharmaceutical Group, New York, NY), has had a revolutionary impact on management. The First International Consultation on Erectile Dysfunction (Paris, 1999), sponsored in part by the World Health Organization (WHO), has indicated that the treatment selected by a patient is influenced not only by issues such as efficacy and safety but by factors such as the ease of administration, invasiveness, reversibility, cost, legal regulatory approval and availability, and possibly the mechanism of action. Worldwide, most patients with erectile dysfunction opt for an oral medication as a direct treatment. The WHO recommendations propose that only pharmacologic treatments that have been tested thoroughly in randomized clinical trials, with subsequent publication of results in peer-reviewed literature, should be considered for general use. Long-term follow-up of all treatment options must be performed to demonstrate durability, continued efficacy and safety, and patient and partner acceptability. New treatment options should not only meet the efficacy and safety criteria mentioned previously but should be compared with available therapies for cost-effectiveness. First-line therapies include oral erectogenic agents and sexual education and counseling. This article reviews current information on sildenafil, the only globally approved and available oral therapy for erectile dysfunction, and on therapies in advanced clinical development, including sublingual apomorphine (Uprima) and IC351 (Cialis).