BACKGROUND The aim of this study was to assess clinical outcomes of arthroscopic surgery for gluteal muscle contracture (GMC) with at least 2 years of follow-up in a large sample. MATERIAL AND METHODS A total of 665 patients who underwent arthroscopic release procedure at our institution between March 2014 and December 2018 and met the inclusion criteria were included in this study. All the patients were operated on by the same surgeon and the surgeon released the contracture band from anterior to posterior starting from the anterior edge of the ITB, the contracture band of the gluteus maximus, and vastus medialis tensor. After exclusion, 544 patients (218 males and 326 females) were finally included. Clinical outcomes at 2 years of postoperative follow-up were evaluated by a combination of several methods, including a new criterion we proposed for postoperative assessment, which included the cross-leg test, difficulty in squatting with legs together, and abnormal gait, the visual analogue scale (VAS), the modified Harris hip score (mHHS), and the satisfaction of patients. RESULTS The average follow-up time was 48.2±14.9 months. Based on the new criteria, 513 (94.3%) patients were evaluated as good, 25 (4.6%) as fair, and 6 (1.1%) as poor. The mHHS increased from 72.1±6.0 (range, 56.0-81.3) to 97.3±2.2 (range, 92.3-100.0) (P<0.001). The VAS decreased from 3.3±1.1 (range, 0-5) to 0.062±0.13 (range, 0-1) (P<0.001). For subjective satisfaction, 526 (96.7%) patients were satisfied, 14 (2.6%) patients were neutral, and 4 (0.7%) patients were dissatisfied. CONCLUSIONS In a large sample, favorable and durable clinical outcomes were observed after the arthroscopic procedure. Clinical symptoms and mHHS showed significant improvement with a minimum 2-year follow-up.