A patient was treated for several years with high doses of opioids for malignant pain. During a recent hospitalization, the patient's pain remained uncontrolled despite escalating doses of various opioids. We suspected that this patient suffered from the clinical phenomenon of opioid-induced hyperalgesia (OIH). The patient was then rotated from her other opioids to methadone, and her pain was adequately controlled within several days. Methadone, because of its NMDA antagonist properties, offers an effective treatment for OIH. The use of methadone for analgesia is complex and should be undertaken only by practitioners who have appropriate experience.