Cerebral venous thrombosis is an uncommon cause of cerebral infarction. A 31-yearoldman complained of headache, weakness, and numbness of the left leg a daybefore being admitted to the hospital. After admission, brain computed tomographyand brain magnetic resonance imaging revealed superior sagittal sinus thrombosiswith cerebral infarction in the right hemisphere. He had no significant medical history. On the fourth hospital day, he suddenly collapsed and died. Medicolegal autopsy wasperformed 3 days later; medical malpractice was suspected. External examinationrevealed a few conjunctival petechiae. Internal examination revealed thrombi in thesuperior sagittal sinus and superficial cortical veins. Thrombi were noted in the pulmonarytrunk and both pulmonary arteries. Upon dissection of the left leg, we foundthrombi in the posterior tibial vein. A microscopic examination revealed vasculitis ofthe same cortical veins, and we therefore assumed that vasculitis of the cortical veinsgave rise to thrombosis. In typical autopsy practice, an examination of the dura materis often overlooked, but careful examination of this region should be performed incases of cerebral infarction in young adults, such as this one.