The authors review four cases of Kaposi's sarcoma that were presented to the Foot Clinics of New York and affiliated North General Hospital during a 1-year period from the fall of 1987 to the fall of 1988. The authors conclude that it is sometimes difficult to diagnose Kaposi's sarcoma and to differentiate between the acquired immunodeficiency (AIDS) form and the classic form. Guidelines for diagnosis and a profile of the AIDS-related and non-AIDS-related Kaposi's sarcoma patient are discussed.