The role of heparin in the treatment of the disseminated intravascular coagulation (DIC) associated with acute promyelocytic leukemia (APL) remains unclear. Between 1974 and 1985, we treated 27 patients with APL using four different chemotherapeutic regimens; 23/27 (85%) had evidence of DIC either at presentation or following the initiation of induction chemotherapy. The coagulopathy was treated primarily with fresh frozen plasma and platelet transfusions; only 2/27 (7%) patients received heparin. Twenty of 27 patients (74%) entered complete remission. Major bleeding or thrombotic complications occurred in 5/27 patients (19%), but 2 of these 5 patients presented after hemorrhage had already occurred. None of the 5 patients with bleeding or thrombosis entered complete remission. All of the hemorrhagic complications due to DIC in our study occurred before 1979, which may reflect changes in the management of leukemic patients. This observation emphasizes the risks inherent in the use of historical controls in this population. In conclusion the DIC associated with APL can be successfully treated with intensive blood product support without the use of heparin.