Alcohol abuse is one of the most common causes of seizures in adults. In a randomized, double-blind study, we compared lorazepam with a placebo for the prevention of recurrent seizures related to alcohol. Over 21 months, we studied consecutive patients with chronic alcohol abuse who were at least 21 years of age and who presented to the emergency departments of two hospitals in Boston after a witnessed generalized seizure. The patients were randomly assigned to receive either 2 mg of lorazepam in 2 ml of normal saline or 4 ml of normal saline intravenously and then observed for six hours. The primary endpoint was the occurrence of a second seizure during the observation period.