The author reviews prior evidence and presents data from his prospective study comparing intramuscular lorazepam with intramuscular haloperidol for control of extreme, agitated psychotic behavior; the data demonstrate that lorazepam is effective and has fewer side effects than haloperidol. The effective intramuscular dose is 1 to 2 mg in conjunction with ongoing neuroleptic antipsychotic treatment. Lorazepam does not prevent future disruptive behavior, and data do not support its use as an agent for maintenance therapy.