We treated by splenic irradiation eight patients with chronic idiopathic thrombocytopenic purpura (ITP, seven cases) or secondary autoimmune thrombocytopenic purpura (one case) who had contra-indications to splenectomy. A total dose of 15 Gy was delivered to the spleen, with left kidney protection. One patient had a good durable response (> 1 year); two patients had a good transient response (of 3 months duration) but they responded again to a second course of irradiation; two patients had only partial response, but have required no other treatments for 2 years; the three remaining patients had no response. Side-effects were minor. Therefore splenic irradiation appears to be a therapeutic option in patients with chronic ITP who have contra-indications to splenectomy.