Background <p>Femoroacetabular impingement syndrome (FAIS) is a prevalent cause of hip pain, yet comparative evidence on the clinical efficacy of hip arthroscopic surgery (HAS) versus non-surgical treatment (NST) remains limited. This study evaluated their short- to mid-term outcomes to inform optimal therapeutic strategies for FAIS.</p> Methods <p>A retrospective cohort study was conducted on 85 patients with FAIS. Fifty-one patients underwent HAS, and 34 received a structured NST program. The Visual Analogue Scale (VAS), modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), and Hip Outcome Score-Activities of Daily Living (HOS-ADL) were compared between the two groups at pre-treatment and 1&#xa0;month, 6&#xa0;months, and final follow-up (mean 21.73&#xa0;months).</p> Results <p>Both groups demonstrated significant improvements, with 100% of patients achieving the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds at the final follow-up. At 1&#xa0;month follow-up, the NST group showed superior outcomes across all scores compared to the HAS group (<i>P</i> &lt; 0.05). However, this pattern reversed at 6&#xa0;months and final follow-up, where the HAS group demonstrated significantly better pain and function scores than the NST group (<i>P</i> &lt; 0.05 for VAS, mHHS, NAHS, and HOS-ADL). The interaction analysis confirmed that improvement was greater in the NST group at 1&#xa0;month follow-up but became greater in the HAS group thereafter.</p> Conclusions <p>Both HAS and structured NST are associated with satisfactory clinical outcomes in FAIS patients at mid-term follow-up. The recovery trajectories, however, differed, with NST associated with faster initial improvement and HAS associated with superior outcomes beyond the 6-month time point.</p>