Familial cases of Kaposi's sarcoma are exceedingly rare. We identified an 85-year-old man with Kaposi's sarcoma. Multiple lesions were present on the feet. Previously, the man's 84-year-old sister presented with similar lesions on the lower extremity. Both siblings were lifelong residents of the United States and were of English/German descent. Neither had risk factors for infection with human immunodeficiency virus (HIV). On histologic examination, lesions in both patients demonstrated vascular slits, hemorrhage, and dense aggregates of spindle cells within the dermis.