Administration of analgesics before surgery can decrease the intra-operative anesthetic requirement and pain during the early post-operative period (pre-emptive analgesia). The objective of this study was to evaluate an intra-muscular preparation of ketoprofen as analgesic in mild to moderate pain in children. In a double-blind placebo-controlled study, 91 healthy ASA I or II children undergoing squint opthalmic surgery was undertaken in the Ophthalmic Services at King Abdel-Aziz University Hospital Riyadh. The postoperative analgesic effects of intra-muscular pethidine and ketoprofen, just after the induction of anesthesia were compared. Patients were randomized to receive ketoprofen (1 mg W kg-1), pethidine (1 mg W kg-1) or saline (0.1 ml W kg-1). Anesthesia was induced and maintained with halothane and nitrous oxide via a facemask. Post-operative pain was assessed by a blinded observer using an objective pain scale. Results revealed that the ketoprofen group had lower post-operative pain scores and required less frequent analgesic therapy in the early postoperative period compared to the pethidine and placebo groups. In contrast, there were no differences in pain scores or analgesic requirements between the pethidine and the placebo groups. It is concluded that the preoperative administration of intramuscular ketoprofen, but not pethidine, provided better postoperative pain control than placebo in children undergoing ophthalmic surgery.