Ultra low doses of opioid antagonists such as naloxone block excitatory opioid receptor pathways may paradoxically enhance morphine analgesia. This case study reports safety and efficacy of ultra low-dose intrathecal (IT) naloxone added to IT morphine for the treatment of severe refractory chronic low back pain. A 56-year-old man with a history of severe chronic low back pain (post-laminectomy syndrome) was evaluated. Extensive multidisciplinary therapies had all failed. Initial treatment at our clinic was a lumbar IT trial of morphine (unsuccessful) up to 50 mg/day. We administered an IT bolus of morphine 2 mg combined with IT naloxone of 20 ng with the patient's consent and approval. The onset of pain relief was within 20 minutes and peaked at 1 hour with a 50 percent reduction in VAS pain score. There were no signs of adverse drug toxicity or hemodynamic compromise. An IT infusion of daily morphine 5 mg and naloxone 50 ng was started. Throughout the 3-year follow-up period, the patient maintained pain reduction of 60 to 80 percent, with a return to daily activities and no further hospitalizations.