Minor head injury is a frequent cause for neurologic consultation and imaging. Most patients with minor head injury will make an uneventful recovery, but in a very small proportion of these patients life threatening intracranial complications occur. We describe a patient on oral anticoagulation therapy, and severely impaired coagulation, with normal head computed tomography on admission, who developed a subdural hematoma requiring surgery 12 hours later. Current guidelines and literature for the management of minor head injury are discussed.