Kaposi's sarcoma (KS) is a relatively common malignancy after kidney transplantation, accounting for up to 80% of all malignancies in developing countries. Aim: To assess the frequency of KS in renal transplant recipients, and determine the impact of demographic factors, immunosuppression and treatment options. Design: Retrospective study in a single centre in South Africa. Methods: Charts and pathology reports of 542 recipients of 623 kidney allografts treated at our institution between 1976 and 1999 were reviewed.