A 71-year-old female patient with classic Kaposi sarcoma (sarcoma idiopathicum haemorrhagicum multiplex) of the lower legs and one hand was treated with intralesional recombinant interferon alpha 2b. After 6 consecutive weeks of intratumoral injection of 1-3 million IU interferon-alpha 2b (Intron A) in three marked lesions, complete remission of intralesionally treated and of untreated tumours was observed. Even 9 months after treatment, the patient is still in complete remission. We conclude that this low dose and well-tolerated treatment schedule with interferon-alpha 2b is effective and a good alternative to radiation or chemotherapy in Kaposi sarcoma.