Purpose: This study was conducted to compare the levels of pain intensity and pain relief between cancer patients and nursing records, and to compare the barriers to pain control between cancer patients and their nurses. Methods: Data were collected from 90 cancer patients who were admitted to three oncology wards and 90 oncology nurses in the same three wards at C University Hospital in G City from July to September, 2012. Results: The most severe pain intensity reported by cancer patients was 6.59 points on the first day of analgesic treatment, while that of their nursing records was 3.98 points on the first day. There were significant changes in pain intensity over time between two groups (F=142.07, p<.001). The highest level of pain relief reported by patients was 2.87 points on the third day, while that of nursing records was 1.67 points on the first day. The score for the social system area of barriers to pain control among the nurses was higher than that of cancer patients (t=-3.69, p=.021). Conclusion: Nurses need to frequently check and to be sensitive to cancer pain. Furthermore, the administrative procedures of narcotic analgesics need to be simplified.