Sixty children with idiopathic thrombocytopenic purpura (ITP) were followed up for 15 to 208 months (mean 120 months) from their first visit. Of these 65% (39 cases) were suffering from acute ITP and 47% of the patients were male. Of the 21 patients with chronic ITP 43% (9 cases) entered remission within five years from the onset of the disease. Conversely patients with chronic ITP for more than five years did not enter remission. Four patients with chronic disease were diagnosed to be other diseases (i.e. three cases were aplastic anemia, the other was Evans' syndrome) after one to four years from the onset. Four patients with chronic ITP for more than five years from the onset are now doing well without any severe bleeding problems. The patients who recovered have had neither problems nor complications. None of the patients died of a cerebral hemorrhage or severe bleeding. We consider that long term outcome of ITP in childhood would be better than that of adult cases.