Purpose: To evaluate minimum 5-year outcomes and conversion rate to total hip arthroplasty (THA) for the treatment of femoroacetabular impingement (FAI) syndrome with an isolated acetabular osteoplasty. Methods: Patients undergoing hip arthroscopy with an isolated acetabular osteoplasty from March 2009 to June 2014 for FAI syndrome with pincer and/or cam morphology and a labral tear were identified. Those who underwent femoroplasty or prior ipsilateral hip surgery or who had previous hip conditions, ipsilateral hip dysplasia, or a Tonnis grade higher than 2 were excluded. Patient-reported outcomes (PROs) collected included Patient-Reported Outcomes Measurement Information System (PROMIS) scores specific to physical functioning and pain interference, modified Harris Hip Score, International Hip Outcome Tool 12, Hip Outcome Score -Activities of Daily Living, Hip Outcome Score-Sport-Specific Subscale, and Numeric Pain Rating Scale. Patients were also queried about secondary surgical procedures and conversion to THA. Results: We identified 86 patients at minimum 5-year follow-up (average, 7.4 years). The average patient age was 39.8 +/- 12.3 years, 70.9% of patients were female, and 7% of patients had Tonnis grade 2. The mean PRO scores were 52.0 +/- 8.9 for the PROMIS physical functioning score, 39.6 +/- 7.5 for the PROMIS pain interference score, 78.7 +/- 12.0 for the modified Harris Hip Score, 73.3 +/- 23.1 for the International Hip Outcome Tool 12 score, 89.9 +/- 12.0 for the Hip Outcome Score -Activities of Daily Living, and 81.4 +/- 21.0 for the Hip Outcome Score-Sport-Specific Subscale. Of the patients, 72.1% achieved the patient acceptable symptomatic state (PASS) according to previously established PASS scores for FAI syndrome treated with hip arthroscopy at minimum 5-year follow-up. The overall rate of revision arthroscopy was 3.5%, and the rate of conversion to THA was 5.8%. Conclusions: An isolated acetabular osteoplasty can provide sustained clinical benefits for the treatment of FAI syndrome with labral tears, with good to excellent PROs and PASS rates and a low rate of conversion to THA at minimum 5-year follow-up.