Pain control in pediatric patients undergoing tonsillectomy remains a dilemma. Tramadol is reported to be an effective analgesic. This prospective, double-blinded, placebo-controlled study was performed to evaluate the analgesic efficacy and safety of submucosal infiltration of tramadol on postoperative pain in children after standard bipolar diathermy tonsillectomy. Following standard bipolar diathermy tonsillectomy was performed, 40 patients were randomized to receive submucoasl infiltration with 2 mg kg(-1) tramadol in 3 ml of normal saline (1.5 ml per tonsil) or normal saline only. The patients in each group were compared postoperatively with regard to the quality of pain control using the objective pain scale (OPS), sedation score and their analgesic requirements. Peritonsillar infiltration of tramadol (group 2) provided superior postoperative analgesia to placebo (group 1) for 4 h after surgery. In addition, group 1 received significantly more doses of paracetamol than group 2 in order to maintain analgesia in the first 12 h after recovery from anesthesia. Peritonsillar infiltration of tramadol appears to be an effective method of providing superior analgesia in the postoperative period when compared to placebo.