Ovarian vein thrombosis (OVT) is an unusual condition mainly observed during the postpartum period. It has not been reported to date in the antiphospholipid syndrome. Two female patients with definite antiphospholipid syndrome, ages 33 years and 73 years, were diagnosed as having OVT by computed tomography (CT) scan, according to the radiologic criteria described by Zerhouni et al. In 1 of the women, the left vein was affected by OVT, while in the other woman, the right vein was affected. One of the patients had a pulmonary embolism; the diagnosis of OVT was established after she underwent a cesarean section and a right atrium thrombectomy. The other patient had no vascular manifestations. OVT was asymptomatic in both patients. Searches for associated thrombophilic states yielded negative results. With the continuation of anticoagulation therapy, the 2 patients have remained in good condition. Resolution of the OVT was observed in the patient who underwent a CT scan during followup. To our knowledge, this is the first report of OVT occurring in the antiphospholipid syndrome. Given that it may develop in the absence of pelvic clinical manifestations, this complication may be underdiagnosed.