Few cases of mexiletine overdose have been reported in the literature. The available case reports have invariably noted significant hemodynamic or electrocardiographic abnormalities. A 41-year-old woman, on mexiletine for arrhythmia control, ingested up to 90 of her 200 mg mexiletine tablets in a suicide attempt. She presented to the emergency department awake with a normal blood pressure and pulse. Shortly afterwards, the patient had a generalized motor seizure, which responded after 40 minutes to intravenous diazepam 100 mg, phenobarbital 1 g and pyridoxine 5 g. Recurrent status epilepticus at one hour required an additional 40 mg of diazepam and a loading dose of pentobarbital. During the entire episode, her electrocardiogram remained normal. The patient's mexiletine level was 20 micrograms/mL (therapeutic 1-2 micrograms/mL) and the patient's urine screen was negative for cocaine. Mexiletine is a group Ib antidysrhythmic agent with electrophysiologic effects similar to lidocaine. Mexiletine has a little first pass hepatic metabolism and a large volume of distribution along with a high lipid solubility, and prolonged central nervous system toxicity may be expected. As with lidocaine, the toxic deaths from mexiletine have resulted from hypotension and bradycardia. The patient reported had a significant mexiletine overdose which resulted in convulsive status epilepticus, but was devoid of hemodynamic or electrocardiographic abnormalities.