OBJECTIVES: To control such cancer pain, it is necessary to select analgesics depending on the intensity of cancer pain, referring to the WHO-recommended 3 step analgesic ladder. This study aimed to provide the Use pattern narcotic analgesics for cancer patient in Korea using claims data. METHODS: To define terminal cancer and severely ill patients close to death who are assumed to be suffering severe pain, 0~120 year old cancer patients who received at least one prescription of a ‘C00-C99’code within top 6 ranks of main disease code and subordinate disease code over 4 years between 2008 and 2011 have been examined. Among those patients, 203,493 patients who confirmed as ‘Death’ in the clinical endpoint and had the date of death were defined as cancer deaths. The status of their narcotic analgesics use was analyzed at 1 month prior to death, 2 months before death, and 3 months before death. RESULTS: The use rate of narcotic analgesics in cancer deaths at 1 month prior to death was 82.6% (168,002 patients). By level of a healthcare facility, prescription frequency was the highest for Morphine, followed by Fentanyl, and Oxycodone for hospital or higher levels at 1 month prior to death. However, Tramadol was most frequently prescribed in nursing hospitals and clinics. And Pethidine which is not a recommended narcotic analgesic for cancer pain patients was prescribed for 38.5% of the entire narcotic analgesic users. The daily amount of narcotic analgesics at 1 month before death is about 1.7-times more than at 3 months before death. CONCLUSIONS: If pain of cancer patients can be appropriately controlled according to the guideline, unnecessary hospitalization and ER visits will be reduced, resulting in improved quality of life of patients and efficient use of medical expenses; however, a number of obstacles exist for cancer pain control in real practice.