With an estimated prevalence of 3–8 problem drug users (mainly heroin) per 1,000 inhabitants in the European Union, it is not unusual to see patients with opioid addictions undergoing elective or emergency surgery. They can sometimes be difficult to treat in the postoperative period because they may have increased pain scores and opioid requirements. Recently, some authors suggested that morphine-induced analgesia could be enhanced by adding low-dose ketamine. We report the successful treatment of an opioid addict patient with this drug combination.