The response to high-dose intravenous immunoglobulin (IVIg) was recently reported to be predictive of outcome after splenectomy in patients with autoimmune thrombocytopenic purpura (AITP). We analysed the records of 75 adults with chronic AITP who received IVIg and subsequently underwent splenectomy. There was no significant difference in the response rate to splenectomy according to whether or not patients had responded to IVIg (81% v 67%, P = 0.36). Age, the time from diagnosis to splenectomy, and the response to steroids were also not significantly associated with outcome after splenectomy. These results indicate that the response to IVIg or steroids is not predictive of the efficacy of splenectomy.