Between August 1966 and December 1989, 989 renal transplant recipients were followed up at the Renal Transplant Unit of Johannesburg Hospital. Seventy-five (7%) patients developed a total of 95 malignancies of which 5 (6%) were Kaposi's sarcoma. All patients received immunosuppressive agents; steroids, azathioprine and/or cyclosporin A. Clinical presentations included both limited skin involvement (1 patient) and disseminated forms of the disease: necrotic oral lesions (1 patient); disseminated skin involvement and lung metastases (1 patient); and widespread skin lesions with lymphadenopathy (2 patients). Four patients responded with complete tumour regression at all sites upon withdrawal of the immunosuppressive drugs. One patient suffered disease progression, and immunosuppression was continued, albeit at reduced dosages. These cases illustrate a relatively rare complication of immunosuppressive therapy. However, complete withdrawal of immunosuppressive drugs may result in sustained complete regression, despite the presence of advanced KS.