The incidence of pain in patients with cancer is high. Pain is also one of the most feared and burdensome symptoms in cancer patients. Unrelieved pain has the negative effects of reducing daily functionality and quality of life. The main indicators of degree of pain and evaluators of how to handle that pain are markers of cancer pain. Complete records are the starting point for pain management. Improvements in pain management require an understanding of the views of patients, staff, health care providers and health care systems about pain assessment and reassessment, and about pain management. As regards the problem of pain education to improve cancer pain assessment and management, opioids are the main drugs for cancer pain management. When nurses care for cancer patients they need to know how to handle their side effects in order to ensure that cancer patients experience the maximum possible pain relief and comfort.