Purpose: Cerebral vessel/sinus thromboembolism is a rare complication of IBD, with DVT and PE accounting for the majority of thromboembolic complications in patients with IBD. Afflicted patients are usually young and without other risk factors for thrombosis other than IBD. Case report: A 21-year-old male with chronic ulcerative colitis (UC) was admitted with exacerbation of colitis despite therapy with corticosteroids, oral mesalamine and 6-mercaptopurine (6-MP). Flexible sigmoidoscopy and biopsies were consistent with severe colitis and negative for infectious etiologies. A CT of the abdomen demonstrated pancolitis. Laboratory values were notable for an elevated ESR and thrombocytosis. After initiation of IV steroids, the patient's colitis improved, but one week after admission, he developed a new bilateral unremitting headache. Over the next 24–48 hours, the patient complained of nausea, vomiting, and dizziness with standing. The neurological exam was significant for increased somnolence, horizontal nystagmus, right-sided facial weakness, dysmetria, and right upper extremity drift. MRI/MRV of the head showed venous infarction involving the cerebellum secondary to venous thrombosis of the bilateral transverse sinuses, straight sinus, and bilateral internal cerebral veins. The patient was started on unfractionated heparin. An attempt at recannulization of the right cerebral sinus was unsuccessful. Infectious etiologies were excluded, and additional testing for hereditary hypercoagulable states was negative. The patient's mental status gradually improved, with complete resolution of neurologic and GI symptoms. He was discharged on mesalamine, oral steroids, and 6-MP with plans for a six month course of oral anticoagulation with coumadin. Discussion: Cerebral sinus and venous thromboses are rare complications of IBD, with a reported frequency of ∼ 0.1%. It has been suggested that this complication is more frequent in UC compared with Crohn's disease. MRI/MRV is the most sensitive non-invasive diagnostic imaging technique, but if the diagnosis is still uncertain, angiography should be considered. Anticoagulation with heparin followed by coumadin is a safe, effective therapy. In a prospective study, 80% patients with cerebral sinus/vein thrombosis treated with heparin made a complete recovery (ISCVT study). Optimal duration of treatment is unknown, but usually given for six months after a first episode. To our knowledge, thrombolysis has been limited to case reports and uncontrolled studies.