Acute biphenotypic leukemia is a very rare malignancy of childhood. Hemorrhage is a frequent complication of these patients. An 18-year-old-male with acute biphenotypic leukemia developed massive gastrointestinal bleeding that was thought to be due to thrombocytopenia during chemotherapy-induced pancytopenia and did not respond to conventional therapy. Although the prothrombin time and the partial thromboplastin time were within normal limits, inspired by the success in thrombocytopenia and platelet function disorders we decided to use recombinant activated factor VII (rFVIIa) as a last resort. After using a single dose (65 mug/kg) of rFVIIa on the fifth day of bleeding, the bleeding ceased immediately. rFVIIa may be a novel therapeutic alternative in leukemia or chemotherapy-associated massive bleeding. (C) 2004 Lippincott Williams Wilkins.