Alkylating agents have been the major group of chemotherapeutic agents associated with an increased incidence of secondary leukemias. In ovarian cancer alkylating agents have resulted in a lesser, although still increased, risk of secondary malignancies. This paper reports two cases of ovarian cancer treated with cisplatin and doxorubicin (Adriamycin, Adria Laboratories, Columbus, OH), and the subsequent development of an acute nonlymphocytic leukemia and a preleukemia syndrome. This regimen does not contain alkylating agents, and has not been associated with leukemia in patients with ovarian cancer. In these two cases, abnormalities of chromosomes 5, 7, 11, and 17 are reported which have been shown to occur in therapy-related leukemia.