Opioids are effective analgesics, but they are often difficult to use properly, due mainly to adverse events, such as constipation, respiratory depression, addiction, tolerance, and opioid induced hyperalgesia. In the past, the problem of opioids around the world was usually caused by drugs traded illegally, so there was no need for medical and social attention in Korea. On the other hand, with the dramatic increase in the therapeutic use of opioids, which commenced more than a decade ago, problems caused by legally prescribed drugs have emerged, and now a more serious opioid crisis is being experienced than in the days of illegal drugs. A growing number of patients are chronically prescribed opioids, and a growing number of health care providers and hospitals suffer from problems related to chronic prescription. Currently, in Korea, it is the time to pay serious attention to achieve the safe and effective use of prescribed opioids. This paper consists of the following parts. 1) A summary of the issues related to chronic pain, opioids, and problems associated with the use of opioids. 2) Some case examples the authors’ experienced. 3) Simple guidelines on the use of opioids in the treatment of chronic non-cancer pain are proposed based on the author’s experience and existing literature. These guidelines are by no means comprehensive, and hopefully in the future, related experts will join forces to develop better guidelines.