Objective: To review the current knowledge on the association of genetic variants with cancer pain. Data Sources: Data-based publications and review articles retrieved from PubMed, CINAHL, and Web of Science, as well as an additional search in Google Scholar. Conclusion: Genetic variability can influence differential pain perception and response to opioids in cancer patients, which will have implications in the optimal personalized treatment of cancer pain. More studies are warranted to replicate findings. Implications for Nursing Practice: Nurses are poised to educate patients on biomarker testing and interpretation and to use precision pain management strategies based on this information.