A 54-y-old man ingested 2 g of bulk laboratory diazepam and was treated with activated charcoal, enhanced diuresis and flumazenil infusion. The treatment resulted in awakening, but the patient had drowsiness, dysarthria, diplopia, and dizziness for 9 d. Blood levels of diazepam and its main metabolite, nordiazepam, were obtained for 1 mo. The half-lives in this benzodiazepine overdose were longer than those seen with therapeutic doses. Benzodiazepines should not be readministrated when patients awake after suicide attempts.