Bizarre electrocardiographic (ECG) changes were found in an 18-year-old girl who had a subdural haematoma following head trauma. The initial diagnosis was of ventricular tachycardia (VT) and she was treated with intravenous anti-arrhythmic drugs and electrical cardioversion, but to no effect. It was later concluded that the ECG appearances were not of a ventricular arrhythmia but were the result of the intracranial pathology. ECG abnormalities related to head injuries have been reported on many occasions, and our case report illustrates how this can create difficulties for the attending clinicians.