A double-blind random study compared lorazepam with diazepam as i.m. premedicants in 84 healthy women undergoing uterine curettage. Anxiety, assessed by a self-rating test by the patient and by a trained observer, was reduced 90 min after both lorazepam (PP<0.01). There was more sedation and a longer recovery time after lorazepam than after diazepam. Amnesia at 24 h after operation (lack of recall rather than lack of recognition) was greater after lorazepam. There was transient local discomfort at the site of the injection in most patients in both groups, but no serious effects. Local erythema was present in 12 patients who received lorazepam and 10 who received diazepam 90 min after the injection, disappearing after 24 h in the former group but remaining in the latter. The incidence of nausea, vomiting and headache in both groups was small and similar, but there was more restlessness and dizziness after diazepam in the early recovery period.