Objective: The aim of this literature study is to investigate how preoperative opioid use affects postoperative pain. We also conducted a questionnaire to assess how patients referred to the pain department of a University hospital in Oslo perceive pain relief after surgery. Background: Perioperative challenges related to chronic opioid-use is a growing global problem. Norway is far from an opioid epidemic, but opioid prescriptions are increasing. The aim of our study is to assess the impact of preoperative opioid use on postoperative pain. We hypothesize that preoperative opioid use represents an issue in Oslo. Methods: Relevant articles and reviews were obtained from PubMed and reviewed. The conclusions were compared to our study conducted between July 2018 and December 2018. 14 patients referred to the pain department for postoperative pain at OUS Rikshospitalet were included. The questionnaire covered patient’s satisfaction, pain scores, length of preoperative pain and opioid use. Results: Our search yielded ten relevant studies and one review. Most of the studies conclude that preoperative opioid use is associated with increased risk for stronger postoperative pain and higher opioid demand. Our study shows half of the included patients did not receive sufficient postoperative pain relief. Whereas the opioid tolerant had a non-significant trend of more preoperative pain, the average postoperative VAS-score for opioid-tolerant (n=7) and opioid-naïve (n=4) patients was 6,0 for both groups. Conclusion: The literature shows that preoperative opioid-use result in more pain post-operatively. We were not able to confirm this finding in our study. However, due to several study limitations, including a small patient number, we cannot draw any definite conclusions from our material.