Amphotericin B, the first commercially significant antifungal drug, has been available for more than 30 years. This polyene macrolide antifungal agent continues to play a major role in the treatment of systemic fungal infections, despite the introduction of newer agents such as the azoles. Given the proved efficacy of amphotericin B--and the increasing number of indications for antifungal agents--an extensive review of this drug is warranted. This paper discusses the clinical uses of amphotericin B, including its application in AIDS-related fungal infections, in neutropenic cancer patients who are persistently febrile, and in infections of the central nervous system, lung, peritoneum, genitourinary system, eye, and skin. The paper also reviews the drug's adverse reactions, with a discussion of administration techniques that may reduce these reactions, and its spectrum of activity, pharmacokinetics, and dosage and administration.