We describe a 69-year-old woman who developed multiple violaceous papules and nodules on both lower extremities. The clinical impression was Kaposi's sarcoma, but the lesions proved to represent multiple ectatic venules that contained papillary endothelial hyperplasia and small foci of an unorganized thrombus. The lesions persisted during a 6-month period of observation. Intravascular papillary endothelial hyperplasia can be observed as an unusual pattern of organization of arterial and venous thrombi or as a focal, incidental microscopic finding in hemangiomas. When lesions of intravascular papillary endothelial hyperplasia cause clinical signs, they characteristically appear as solitary, slowly growing nodules, usually on the upper extremities or head. Intravascular papillary endothelial hyperplasia has not previously been noted to simulate Kaposi's sarcoma.