Cancer pain is often suboptimally managed. The underestimation and undertreatment continues to be a problem despite the availability of consensus-based guidelines. Most patients with cancer develop pain. The prevalence and severity of pain among cancer patients varies according to primary and metastatic sites and stage of disease. Opioid therapy is the cornerstone of management of severe chronic pain in the field of cancer patients and in general in palliative care medicine. Since this class of drugs is the cornerstone of the treatment, optimizing its use may be useful in clinical practice. For this purpose we focused on 4 distinct issues: 1) How to implement the use the opioids in cancer patients; 2) How to optimise the use of morphine in cancer patients; 3) The management of side effects and opioid switching; 4) What is the role of other potent opioids. A holistic approach including an appropriate use of opioids may improve pain control in most cancer patients, particularly for those with advanced disease.