Dexketoprofentrometamol (DKP), is a tromethamine salt of the water-soluble S-enantiomer of ketoprofen. As with all other non-steroidal anti-inflammatory agents, the most common side effect of DKP is gastric complications. In this paper, we report a case of dystonic reaction after intravenous DKP use. A 24-year-old man was admitted to our hospital after suffering a leg burn from boiling oil. He had no drug hypersensitivity. An intravenous preparation containing the active ingredient DKP was injected for analgesia, after which the patient experienced an involuntary flexion response in both upper extremities. With a suspected diagnosis of dystonia, biperiden lactate 5 mg/ml was administered via the intramuscular route and the contractions abated within 30 seconds of the injection.As non-steroidal anti-inflammatory agents are commonly used and prescribed in emergency departments, it should be kept in mind that an acute dystonic reaction can develop against one of these agents, DKP.