BACKGROUND: The anterior cruciate ligament (ACL) is an important ligament of the knee joint. Avulsion fracture of the tibial insertion point of the ACL accounts for 14% of all ACL injuries. However, no gold standard approach for treating ACL avulsion fractures exists. OBJECTIVE: This study aimed to evaluate the clinical effect of the treatment of ACL avulsion fracture with gate-shaped Kirschner wire fixation via arthroscopy. METHODS: Clinical data of 46 patients (male:female, 1:1.3; age, [Formula: see text] years) with ACL avulsion fracture who were treated with gate-shaped Kirschner wire fixation via arthroscopy in the People’s Hospital of Zhongjiang County from February 2018 to March 2021 were collected. The clinical effect was retrospectively analyzed using preoperative and postoperative joint range of motion (ROM), Lysholm score, and International Knee Documentation Committee (IKDC) score. RESULTS: After the operation, the ROM ([Formula: see text] deviation, [Formula: see text] and [Formula: see text], [Formula: see text]), Lysholm score ([Formula: see text] and [Formula: see text], [Formula: see text]), and IKDC score ([Formula: see text] and [Formula: see text] at the last follow-up, [Formula: see text]) significantly increased. CONCLUSIONS: The Kirschner wire fixation technique via arthroscopy displayed good therapeutic efficacy, was simple and effective, and is worth recommending for treating ACL avulsion fractures.