Valproate is an antiepilcptic drug that has broad spectrum activity against several types of seizure. Little information is available about the use of valproate for acute loading of patients when a rapid increase in serum level is needed. We describe the use of intravenous valproate in 20 adults with epilepsy. In each case, a loading dose was calculated by multiplying the patient's body mass, desired change in serum level, and estimated volume of distribution. The mean dose (± SD) administered was 1420 ± 440 mg (19.4 ± 5.4 mg/kg). In four patients, the dose was infused at 20 mg/min; in all other patients, infusions were performed at 50 mg/min. The infusions were tolerated well and few clinical side effects were observed. Postinfusion levels were drawn and the apparent volume of distribution was calculated to be 0.22 ± 0.04 L/kg. The results indicate that intravenous valproate may be used to quickly and efficiently increase scrum levels in patients with epilepsy.