One hundred patients aged 5-13 yr were randomly allocated to four groups in a double-blind study of premedication. Drugs studied were lorazepam, diazepam and trimeprazine. A placebo group was included. All the drugs appeared satisfactory as premedicants. Lorazepam induced the most sedation immediately after surgery, but by 4 h lorazepam and diazepam appeared similar. Lorazepam produced better amnesia than the other drugs. There were no untoward side-effects and no cardiorespiratory depression in any group. Lorazepam appears a suitable premedicant for children.