The clinical course of KS is highly variable, ranging from minimal disease to explosive growth. Extracutaneous spread is common, involving most frequently the oral cavity, GI tract, lungs, and lymph nodes. Both corticosteroid therapy and opportunistic infections are associated with the development of KS and with exacerbation of pre-existing KS in HIV-infected patients. A typical initial evaluation includes a thorough physical examination, fecal occult blood test, chest roentgenogram, and CD4+ T-lymphocyte count. The staging system most commonly used groups patients according to extent of tumor, immune status, and severity of systemic illness. After adjusting for prognostic factors, the most important of which is the median CD4+ T-lymphocyte count at presentation the survival of patients with KS is improving as the AIDS epidemic matures.