This middle-aged man was admitted after a generalized tonic-clonic seizure that occurred at home. Physical examination did not reveal any significant external wounds as a result of the seizure and there were no focal neurological signs. However, examination of the oral cavity showed presence of a haematoma at the side of the tongue. This occasionally occurs in patients with generalized tonic-clonic seizures as a result of clenching of the teeth that may result in biting of the cheek or tongue.