Background and Aims: Cancer pain guidelines remain confined due to implementation barriers, preventing them from attaining a global perspective. The guidelines must be robust in development and inculcate high-quality content to achieve practical utility. Quality indicators related to safe opioid practice empower effective guideline implementation. Methods: The protocol was registered prospectively in PROSPERO (CRD42021244823). Guidelines published over the last decade providing insights into cancer pain management and incorporating safe opioid practice were evaluated. The review’s primary outcome was to evaluate the quality of cancer pain guidelines. Appraisal of guidelines for research and evaluation II (AGREE II) instrument was used to assess a guideline’s quality. The ADAPTE collaboration-guideline adaptation resource tool kit (ADAPTE) provided insights into its adaptation based on specific questions within the guideline. Results: Fourteen cancer pain guidelines met the eligibility criteria and were included for quality evaluation. Eight guidelines were evaluated with combined AGREE II and ADAPTE process, attaining >66.7% in the rigour of development domain score, summated scaled domain score, and specific ADAPTE tools to evaluate the quality of each guideline. The intra-class correlation coefficient was utilised for resolving inter-rater agreement. ‘Safe opioid practice’ within a guideline was assessed for quality content implementation. Conclusion: Combined AGREE II and ADAPTE identified four cancer pain guidelines, namely Ministry of Health Malaysia, National Comprehensive Cancer Network, NCEC-National Clinical Guideline, and World Health Organization, which were of the highest quality and incorporated safe opioid practice effectively.