Interferon (IFN)-alpha therapy was presented as a possible treatment for refractory immune thrombocytopenic purpura (ITP). We used 3 x 10(6) U recombinant IFN alpha, subcutaneously three times a week, every other day, for a total of 12 doses, in five children with refractory ITP. Three patients showed no response and were classified with Type III. One patient gave a partial response, and the other one had been in remission for 71 weeks as of this writing. This is the longest remission period reported for IFN therapy. The patients were classified Types IIb and I, respectively. The therapy was well tolerated. We conclude that further studies are to needed evaluate IFN-alpha therapy in childhood ITP.