This report concerns a 37-year-old patient with ovarian cancer and a paradoxical cerebral embolism as the initial symptom. She developed acute onset of left quadrantic hemianopia during coughing. Brain magnetic resonance imaging showed an acute multiple infarction, and a simultaneous acute pulmonary embolism was observed. Transesophageal echocardiography showed a patent foramen ovale, multidetector row computed tomography an ovarian tumor and infarction of the spleen, whereas multidetector row computed tomography venography showed right iliac vein compression by the ovarian tumor. The diagnosis was stage Ic ovarian cancer. Because blood stasis of the pelvic vein is a major risk factor for venous thrombosis, the presence of a patent foramen ovale should alert physicians to examine not only veins in the lower extremities but also the pelvic and intra-abdominal veins as a source paradoxical embolism.