In this report we describe a case of extensive cerebral venous thrombosis in a patient with Evans syndrome. A 19-year-old male patient with Evans syndrome was admitted to the hospital with the complaints of headache, convulsive seizure, and vomiting. The cerebral venous thrombosis including left lateral, left sigmoid, straight sinus, and vena jugularis interna was diagnosed by cerebral magnetic resonance angiography. When the thrombosis developed, he was in hematological remission and he was not receiving any medications except lamivudine for chronic hepatitis B infection. As a genetic prothrombotic risk factor, he had heterozygous prothrombin G20210A gene mutation. His clinical and radiologic findings improved after unfractionated heparin and subsequently with coumadin therapy. On follow-up, cerebral venous thrombosis reoccurred in different localizations, but complete recanalization could be obtained with antithrombotic therapy. We present the case since the association of cerebral venous thrombosis and Evans syndrome is very rare.