The effectiveness of high-dose intravenous methylprednisolone (HIVMP) in inducing an initial remission was examined in a child with acute nonlymphoblastic leukemia (ANLL). Dramatic clinical and hematological improvement with 7% marrow blasts was obtained in 3 weeks with HIVMP treatment without giving any other antileukemic drugs. Based on the results of this preliminary observation we suggest that high-dose methylprednisolone (20-30 mg/kg) might be a useful approach when applied as an initial short treatment in childhood ANLL.