There is a lack of report of conscious sedation used as a last resort therapy for alleviating severe symptoms. To achieve this goal, dexmedetomidine appears to be a promising option. We report a case of successful two-month long treatment of intravenous (IV) dexmedetomidine added to hydromorphone for intractable cancer pain, restlessness, severe sleep disorder, anxiety, and craving symptoms in a 40-year-old man with active polysubstance use, receiving escalating doses of opioids for intractable abdominal cancer pain together with benzodiazepines. Under dexmedetomidine infusion at 1.2 μg/kg/hour, his symptoms markedly decreased. He could sleep at night and find respite during the day while continuing walking, eating, and other activities. Long-term conscious sedation with IV dexmedetomidine was well tolerated. We did not observe anxiety or agitation rebound during short periods of discontinuation of the infusion. Neither side effects nor tolerance were observed over time. Further research is needed to investigate the indications for conscious sedation and analgesia with dexmedetomidine in palliative patients with a prognosis that is longer than few weeks or uncertain.