Ketorolac tromethamine (Toradol [Syntex, Palo Alto]), a new commercially available nonsteroidal antiinflammatory drug (NSAID), has appropriate solubility and minimal tissue irritation, making it suitable for intramuscular injection. Previously, NSAID have only been available for oral use in the United States for the treatment of pain. Ketorolac, the most potent NSAID known, relieves pain through inhibition of arachidonic acid synthesis at the cyclooxygenase level and has no central opioid effects. The results of previous studies using parenteral ketorolac in combination with patient administered narcotics have shown a 40 percent reduction in narcotic requirements. However, ketorolac is presently only approved for intramuscular injection and oral use in the United States. In a prospective, randomized study, we compared intramuscular ketorolac in combination with patient controlled intravenous narcotic analgesia (morphine) (PCA-M) to PCA-M alone for the control of pain after extensive colonic resections. The combination of intramuscular ketorolac and PCA-M provided equal pain relief with no increased side effects when compared with narcotics alone. However, narcotic requirements of the patients were decreased by an average of 45 percent. Ketorolac and narcotics in combination provide effective postoperative pain relief and significantly decrease narcotic requirements. This combination may be particularly beneficial in the subpopulation of patients especially prone to narcotic related complications.