Cytopheresis techniques have proven useful in the provision of platelets and granulocytes for transfusion to the pancytopenic patient. Mechanical cell removal has been applied to the treatment of chronic myelocytic and lymphocytic leukemias and the Sezary syndrome. We have treated a 16-year-old pregnant acute myelomonocytic leukemia (AMML) patient for 12 weeks solely with the use of intensive leukopheresis utilizing batch processing centrifugation and packed red cell transfusions. The patient presented with a white blood cell count of 54,000/mm3 with 64% myelomonoblasts, a platelet count of 45,000/mm3, marked gingival hyperplasia, and splenomegaly. Patient had a normal spontaneous delivery of a 2.5-kg male infant without complications. At the time of delivery, 12 weeks later, the white blood count had fallen to 4,9000/mm3 with 8% blasts and the platelet count had risen to over 100,000/mm3. Gingival hyperplasia decreased and the patient felt well. We have treated an additional small group of patients with acute myelogenous leukemia (AML) with high white counts with short term intensive leukopheresis followed by chemotherapy with promising results.