Ethical problems presented by opioid-dependent patients suffering from pain are challenging, but can be guided by simple principles of ethical medical practice. This chapter presents three case studies on opioid therapy for addicted patients. The first is of a 35-year-old woman with chronic leg pain secondary to vascular damage from previous recurrent groin infections associated with intravenous opioid use. The second deals with a 34-year-old man with acute alcohol poisoning. The third focuses on a 40-year-old man with a significant history of drug misuse. The chapter then explains their resolutions from the UK perspective. A major problem with pain management in the patient with opioid dependency is lack of physician knowledge about appropriate prescribing; education of physicians is key to developing reasonable prescribing practices. A principle like that of "double effect" might be useful in defining appropriate physician behavior in relieving pain in the potentially dependent patient.