Ketorolac is an effective and popular long-lasting analgesic that is especially useful in the emergency department and postoperatively. It is comparable in potency to the opiates but is preferable to them in many instances. Its relative overall safety as compared to the opiate analgesics may generate an unjustified complacent attitude toward its safety in all instances. Ketorolac, however, is an NSAID, and its major toxicities include those of other NSAIDs. Bronchospastic- and anaphylactic-type life-threatening reactions have occurred with its use. The prescribing physician must be aware of this potential complication and should always obtain a patient's complete history, including information regarding aspirin and NSAID intolerance, asthma, rhinitis, and nasal polyps, before administering it. Its use is contraindicated under those circumstances. When ketorolac is administered to asthmatics, it should be done with extreme caution and monitoring, especially when the intramuscular preparation is used. In this way, morbidity, health care costs, and the potential for mortality will be kept at a minimum.