Chronic Immune Thrombocytopenic Purpura (C-ITP) is a heterogeneous group of disorders manifesting as thrombocytopenia of greater than six months duration. To better understand its natural history, and detect trends of response to therapy and of outcomes, a ten-year retrospective survey of C-ITP diagnosed in Canadian children from age 6 months to under 20 years was conducted in 2004. A standardised form for capture of anonymous data on each patient was completed and returned from 11 institutions, including the three largest Canadian Pediatric Hematology/Oncology centres. Of the total of 243 forms received, 213 cases met the inclusion criteria. Male:female::1:1.3. Mean age at diagnosis of C-ITP was 7.9 years (range 8 months - 17.7 years). Mean platelet count at diagnosis and mean duration of C-ITP were 46 x 109/L (range 1 - 145 x 109/L) and 2.9 years (range 0 - 9.7 years) respectively. Primary ITP was the underlying diagnosis in 85 % of cases. Internal hemorrhage was documented in 1 % of patients. Treatments (either singly or in combination) with drugs, IVIG, anti-D, or monoclonal antibody, were administered in 91 % of cases. Five percent of patients received blood transfusions for treatment of bleeding episodes; 18.1 % underwent splenectomy. Information gained from this data base will be used in developing management guidelines for C-ITP, and will provide the foundation for establishing a Web-based Canadian National C-ITP Registry.