Pain is one of the major symptoms that cancer patients suffer from before, during and even after treatment. The mainstay of pain management for cancer patients is the administration of opioid analgesics. This thesis aims to discuss the pharmacology of opioid analgesics, the mechanism of action by which they help to relieve pain and therefore, their use in the management of cancer related chronic pain. The most common side effects of opioid analgesic use will also be included and some potential non-opioid pharmacological and non-medicinal alternatives for cancer pain management. The use of opioid analgesics in the management of cancer related chronic pain is an important topic to discuss in modern healthcare because of the current rapidly increasing use of opioid analgesics globally which has a detrimental effect on the health and lives of many.