Background: Hip arthroscopy is rapidly advancing, with positive published outcomes at short- and midterm follow-up; however, available long-term data remain limited.Purpose: To evaluate outcomes of primary hip arthroscopy at a minimum 10-year follow-up at 2 academic centers by describing patient-reported outcomes and determining reoperation and total hip arthroplasty (THA) rates.Study Design: Case series; Level of evidence, 4.Methods: Patients with primary hip arthroscopy performed between January 1988 and April 2013 at 2 academic centers were evaluated for postoperative patient-reported outcomes-including the visual analog scale, Tegner Activity Scale score, Hip Outcome Score Activities of Daily Living and Sport Specific subscales, modified Harris Hip Score, Nonarthritic Hip Score, 12-item International Hip Outcome Tool, surgery satisfaction, and reoperations.Results: A total of 294 patients undergoing primary hip arthroscopy (age, 40 +/- 14 years; 66% women; body mass index, 27 +/- 6) were followed for 12 +/- 3 years (range, 10-24 years) postoperatively. Labral debridement and repair were performed in 41% and 59% of patients, respectively. Of all patients who underwent interportal capsulotomy, 2% were extended to a T-capsulotomy, and 11% underwent capsular repair. At final follow-up, patients reported a mean visual analog scale at rest of 2 +/- 2 and with use of 3 +/- 3, a 12-item International Hip Outcome Tool of 68 +/- 27, a Nonarthritic Hip Score of 81 +/- 18, a modified Harris Hip Score of 79 +/- 17, and a Hip Outcome Score Activities of Daily Living of 82 +/- 19 and Sport Specific subscale of 74 +/- 25. The mean surgical satisfaction was 8.4 +/- 2.4 on a 10-point scale, with 10 representing the highest level of satisfaction. In total, 96 hips (33%) underwent reoperation-including 65 hips (22%) converting to THA. THA risk factors included older age, higher body mass index, lower lateral center-edge angle, larger alpha angle, higher preoperative Tonnis grade, as well as labral debridement and capsular nonrepair (P <= .039). Patients undergoing combined labral and capsular repair demonstrated a THA conversion rate of 3% compared with 31% for patients undergoing combined labral debridement and capsular nonrepair (P = .006). Labral repair trended toward increased 10-year THA-free survival (84% vs 77%; P = .085), while capsular repair demonstrated significantly increased 10-year THA-free survival (97% vs 79%; P = .033).Conclusion: At a minimum 10-year follow-up, patients undergoing primary hip arthroscopy demonstrated high satisfaction and acceptable outcome scores. In total, 33% of patients underwent reoperation-including 22% who underwent THA. Conversion to THA was associated with patient factors including older age, higher Tonnis grade, and potentially modifiable surgical factors such as labral debridement and capsular nonrepair.