BACKGROUND A prospective study was conducted to investigate the presence of anterograde amnesia in those who attempted suicide by benzodiazepine overdose and to study the correlation with sedation. METHODS In 43 patients who attempted suicide by taking benzodiazepines, memory was tested with a 15-word memory recall task. The immediate and delayed recall on the first day after admission (day 1) and 24 hours later (day 2) were rated. Each patient and the interviewer scored the patient's degree of sedation on a visual analogue scale. Patients also had to try to recognize, from photographs, the psychiatrist with whom they had spoken the day before. RESULTS The ratings of immediate and delayed recall were significantly lower on day 1 than on day 2. Subjective ratings of sedation of the patients were not significantly higher than the ratings of the observer. Less than half of the patients recognized the psychiatrists and knew that they were the ones they had spoken to the day before. CONCLUSIONS Anterograde amnesia is present in suicide attempters who take overdoses of benzodiazepines. The implications of this finding for the assessment of suicide attempters during admission are discussed.