A 20-year-old female ingested an unknown quantity of minoxidil tablets as a suicide gesture. She presented to the emergency department about 90 minutes later with tachycardia, diffuse T wave inversion, and S-T segment depression on the ECG, labile hypotension, and a substantially elevated total serum minoxidil concentration of 3140 ng/mL. She responded to supportive therapy with intravenous fluids, and was discharged 32 hours later with stable blood pressure and mild residual tachycardia. The clinical toxicology, treatment, and previous case reports of minoxidil overdose are reviewed.