Nineteen children with chronic idiopathic thrombocytopenia (ITP) were treated with a single intravenous injection of methylprednisolone (MP), 15 mg/kg/day, for 3 consecutive days. The 3-day pulses gave rise to a positive and fast therapeutic response with increase of the platelet count in about three quarters of the patients. The platelet count remained above 50 X 10(9)/1 for more than 1 month in 10 children. Eight out of them still presented a safe platelet count (greater than 50 X 10(9)/1) 4 months after the onset of the therapy. The MP therapy improved the platelet count more in the older children and possibly in the females. No severe side effects were observed. Our results suggest that this therapeutic approach could be useful in the management of acute bleeding episodes in children with chronic ITP.