Patients with inflammatory bowel disease are known to have hypercoagulability and an increased risk for venous thromboembolism. The deep veins of the lower extremities and the pulmonary veins are the most common sites of thrombosis in ulcerative colitis. However, hepatic vein thrombosis (Budd-Chiari syndrome) is a very rare extra-intestinal complication of ulcerative colitis in children. We describe a case of hepatic vein thrombosis in a 15-year-old girl with ulcerative colitis who presented with abdominal pain and hematochezia. Doppler ultrasonography and an abdominal CT scan revealed the characteristic filling defects caused by large thrombi in both hepatic veins. These lesions were successfully treated with conventional management for ulcerative colitis and anticoagulation therapy.