The association of Kaposi's sarcoma with malignant lymphoreticular diseases and immunosuppressive therapy is well documented. This report describes an elderly man who presented with fulminant Wegener's granulomatosis that responded to treatment with cyclophosphamide and corticosteroids. Rapidly progressing cutaneous Kaposi's sarcoma developed ten weeks after the start of immunosuppressive therapy yet regressed on discontinuation of the corticosteroid therapy, despite continuation of cyclophosphamide therapy. To our knowledge, this is the first reported case of Kaposi's sarcoma occurring in association with Wegener's granulomatosis. The literature on Kaposi's sarcoma in immunosuppressed patients is reviewed.