Acute leukemias tend to affect a younger population and are much more common in pregnant patients than chronic leukemias are. We report a case of acute lymphoblastic leukemia diagnosed during the third trimester presenting with organomegaly and thrombocytopenia. Delivery of the fetus by cesarean section was decided because of the fulminant nature of the acute leukemia within days of admission. Bone marrow biopsy revealed acute lymphocytic leukemia, French American-British L-2 subtype B cell immunotype. A left ovarian mass was identified during the cesarean section which later proved to be lymphoblastic infiltration. The patient was started on induction chemotherapy consisting of vincristine, daunorubicin, prednisolone, and L-asparaginase immediately after the diagnosis. The patient died of Acinetobacter septicemia 18 days after the first admission.