Abstract:[Objective] To investigate the clinical outcomes of hip arthroscopy for femoroacetabular impingement (FAI) in adolescents. [Methods] From January 2016 to September 2018, 21 adolescent patients underwent hip arthroscopic surgery for FAI. The clinical and im- aging data were evaluated. [Results] As findings of arthroscopic examination, 7 case were of cam-type impingement, 2 were of pincer-type and 12 were mixed-type, and 19 cases were accompanied with impingement of the anteroinferior iliac spine among the 21 patients, whereas all 21 cases were accompanied with labrum injury. Corresponding arthroscopic treatment was performed to the lesions with no complica- tions, such as nerve injury, intraarticular infection or symptomatic thrombosis. The VAS scores significantly decreased (P<0.05) , while the mHHS and iHOT-12 scores significantly increased at 12 and 24 months postoperatively compared with those before surgery (P<0.05) . Ra- diographically, the α angle and lateral center edge angle (LCEA) significantly reduced (P<0.05) , while the femoral head neck offset (FH- NO) significantly increased (P<0.05) , and there was no significant change in LCEA (P>0.05) postoperatively compared with those before operation. Up to the latest follow-up, all the 21 patients had no obvious hip degeneration. According to Oxford method, bone growth and de- velopment remained normal after surgery in all the adolescents. [Conclusion] Hip arthroscopy is an effective treatment for FAI in adoles- cents without affecting bone growth and development.