INTRODUCTION: The aim of this research was to compare postoperative early stage (24 hours) visual analogue scores (VAS) following ultrasound-guided interscalen brachial plexus block (ISBPB) and postoperative intraveunos patient controlled analgesia (PCA) after general anesthesia (GA) in patients undergoing arthroscopic shoulder surgery. METHODS: This was a retrospective study. The subjects included 98 patients who underwent ISBPB+ GA (Group ISBPB) and GA + iv PCA (Group GA) for elective arthroscopıc shoulder surgery between August 2016 and August 2017. Postoperative visual analogue scale (VAS) pain scores at rest and during activity at 30th min, 2, 6, 12 and 24th hours, the total amount of morphine consumed, the first analgesia requirement time were evaluated by postoperative patient controlled analgesia (PCA) devices. RESULTS: The demographic characteristics of the patients were similar (p>0.05). There was a statistically significant difference between the two groups in terms of resting and active VAS scores according to time (p<0.001). The VAS scores were lower in the ISBPB group in the first 12 hours than in the PCA group (p<0.001). Total amount of consumed morphine were lower, and the first analgesia requirement time were much more in the ISBPB group than in the PCA group (p<0.001). However, there was no significant difference in complications between the two groups (p<0.05). DISCUSSION AND CONCLUSION: Pain levels after arthroscopıc shoulder surgery showed that ISBPB had a superior effect to GA in providing pain relief, but ISBPB was similar to GA in terms of postoperative complications.