PURPOSE: The purpose of this study was to evaluate the spontaneous remission rate in children with chronic ITP. METHODS: The medical records of 21 patients diagnosed with chronic ITP and followed for at least 6 months at Hanyang University Hospital between Mar. 1985 and Feb. 1997 were reviewed. Complete remission(CR) was defined as a recovery of platelet count of more than 100x109/L and partial remission(PR) was defined as a recovery of platelet count of 50-100x109/L, maintained for at least 6 months. RESULTS: Of 21 patients, 9 boys and 12 girls, the mean age at diagnosis was 5.5 years (0.4~15.5 years). The mean platelet count at diagnosis was 26.5x109/L(2-86x109/L). Of 21 patients, 5 with persistent thrombocytopenia and severe bleeding tendency underwent splenectomy. With a median follow up of 39.5 months after splenectomy, 4 achieved CR. The time to CR of the 4 patients were 2 weeks, 13.6, 18.6, 31.0 months, respectively. Of 16 patients, excluding 5 splenectomized children, 6 achieved CR and 4 PR. With a median follow-up of 21 months, the predicted spontaneous CR and PR rate at 5 years were 37.5%, and 68.7%, respectively(The percentage of PR includes that for CR). No serious complications including ICH or death were observed. CONCLUSION: Our study indicates that many cases of chronic ITP in childhood may remit without therapy even several years from onset. Splenectomy should be delayed as long as possible and reserved for the symptomatic and severely thrombocytopenic patient.