We performed a retrospective analysis of bone marrow examination (BME) in the management of Chinese adult patients less than 60 years of age with isolated thrombocytopenia at presentation. Eighty-three patients with a median age of 39 years presenting with isolated thrombocytopenia (median platelet count: 38 × 109/l) had routinely undergone BME as part of the laboratory investigations during the period from January 1996 to December 1999. All 83 patients had bone marrow findings of active marrow suggesting causes due to peripheral destruction. All of these patients responded to steroid or intravenous immunoglobulin (IVIg) therapy at presentation if their platelet counts were significantly low or if they had mucosal bleeding. Eighty-one of the 83 patients, after a median of 20 months follow-up, were finally diagnosed as having idiopathic thrombocytopenic purpura (ITP). The remaining two patients were finally confirmed as cases of systemic lupus erythematosus (SLE). Our results suggest that BME is not helpful in the diagnosis of isolated thrombocytopenia or suspected ITP in adult patients at presentation, provided that a thorough clinical history and physical examination are undertaken and that the blood count and peripheral blood smear show no abnormalities apart from the thrombocytopenia.