Cerebral venous sinus thrombosis (CVST) is an uncommon cause of stroke and accounts for 0.5-1% of all stroke cases. A 23-year-old woman who was 33 weeks pregnant visited the hospital complaining of a right temporo-parietal headache which had lasted for 5 days. The headaches were new onset, unilateral, and non-throbbing and were associated with nausea and vomiting. She had no significant past medical history. There was no history of trauma, illicit drug abuse, smoking, or alcohol use. There was no family history of coagulopathy or thrombophilia. A neurological examination demonstrated bilateral grade 2 papilledema. Brain MRI and MR venography were performed that showed a left fronto-parietal subdural hematoma with left transverse sinus thrombosis. Genetic analysis showed a heterozygotic mutation of MTHFR and a homozygotic mutation for Angiotensin-Converting Enzyme (ACE). Screening for other hypercoagulable states were negative. Anticoagulant therapy with a therapeutic dose of heparin was administered intravenously immediately and her symptoms disappeared one week after admission.