Two hundred patients with histories of chronic alcoholism and recent bouts of heavy and uncontrolled drinking were treated for alcohol withdrawal symptoms through the use of chlordiazepoxide and thiamine. One hundred of these patients, chosen at random, also received diphenylhydantoin. No withdrawal seizures occurred in either group, nor were any other differences observed. Patients with a history of previous withdrawal seizures were included in both treatment groups. These observations suggest that when adequate doses of chlordiazepoxide and thiamine are used during alcohol withdrawal, no additional anticonvulsant drug is needed to prevent seizures.