Pain was and in part still is a constant feature of surgical practice: before, during and after surgery. To start with painful symptoms represent a fundamental diagnostic element, given that in over 60% of cases pain is the primary indication for surgery. During the operation, pain used to constitute the main impediment to the surgeon's activities, until the introduction of ether and the birth of modern anesthesia. Lastly, the postoperative period is also painful so much so that whereas until fifty years ago patients were above all afraid of the operation, patients nowadays are concerned about the pain during the days after the operation. Moreover, over 50% of patients undergoing surgery are unsatisfied with the treatment of postoperative pain, in spite of the fact that drugs are available which enable us to control it. The authors studied the quality of postoperative analgesia in 357 patients, who received treatment with ketorolac tromethamine 30 mg i.v. on leaving the operating theatre, and subsequently i.m. every 8 hours starting from 3 hours after surgery. The use of ketorolac tromethanine demonstrated effective analgesia and was well accepted by patients, without revealing any particular collateral effects.