A 73 year-old male with a Kaposi's sarcoma presenting as multiple, red-purple papules and nodules on the vermillion border and as ulcerations on the labial mucosa, is described. No other skin or organ involvements were found. The main clinical and histopathological characteristics of the classic form of Kaposi's sarcoma are briefly discussed and the recent aspects on tumor histogenesis and pathogenesis are analysed.