Benzodiazepines ameliorate or prevent the symptoms and complications of moderate to severe alcohol withdrawal, which can include autonomic hyperactivity, agitation, combativeness, hallucinations, seizures, delirium, and death. The benzodiazepines most commonly used for this purpose are lorazepam, chlordiazepoxide, oxazepam, and diazepam. It is widely asserted that no member of this group is superior to the others for treatment of alcohol withdrawal. However, of these, diazepam has the shortest time to peak effect, which facilitates both rapid control of symptoms and accurate titration to avoid over-sedation. Furthermore, diazepam and its active metabolite, desmethyldiazepam, have the longest elimination half-lives, so their levels decrease in a gradual, self-tapering manner, resulting in a smoother withdrawal, i.e., a lower incidence and severity of both breakthrough symptoms and rebound phenomena, including a possibly decreased seizure risk. Importantly, the fear of increased risk of over-sedation with diazepam compared with other benzodiazepines is based on a misunderstanding of its pharmacokinetics and is unfounded. Similarly, the notion that diazepam should be avoided in patients with liver disease and elderly patients to avoid prolonged over-sedation is based on no more than conjecture. In fact, there is clinical evidence that diazepam is safe for the treatment of alcohol withdrawal in these patients when administered using a simple symptom-based approach. There is one instance in which diazepam should not be used: when intramuscular administration is the only option, the lipophilicity of diazepam can result in slow absorption-either lorazepam or, when rapid control of symptoms is required, midazolam should be used. The comparative pharmacokinetics of the benzodiazepines used in the treatment of alcohol withdrawal together with a comprehensive review of the literature on their use strongly suggest that diazepam should be the preferred benzodiazepine for the treatment of patients experiencing moderate to severe alcohol withdrawal under most circumstances.