BACKGROUND: Chronic lateral ankle instability (CAI) is a common condition that can be effectively treated with lateral ankle ligament reconstruction to restore ankle stability and function. The aim was to assess the functional outcomes of arthroscopic lateral ligament reconstruction using the Manchester-Oxford Foot Questionnaire (MOXFQ), Visual Analog Score (VAS) and Euroqol-5D-5L (EQ-5D) patient-reported outcome measures (PROMs). METHODS: This prospective series included 36 consecutive patients who underwent isolated arthroscopic lateral ligament reconstruction for CAI between November 2020 and November 2022 with minimum 12-month follow up. All patients completed the MOXFQ, VAS, and EQ5D PROMs preoperatively, and a minimum of 12 months postoperatively. The MOXFQ is a foot and ankle-specific PROM that assesses foot and ankle function, the VAS measures pain and the EQ5D evaluates general health-related quality of life. RESULTS: Patients were followed up for 12-25 months. In all patients, there was significant improvement in all postoperative PROMs (p <
0.05). The MOXFQ index decreased from 59.1 ± 19.2-13.5 ± 18.1 (p <
0.01), EQ-5D index increased from 0.607 ± 0.224-0.854 ± 0.175 (p <
0.01) and VAS pain decreased from 36.6 ± 22.3-13.6 ± 18.4 (p <
0.01).A total of 6 patients(16.3 %) were lost to follow up and mean follow-up time was 1.63 ± 0.54 years. CONCLUSION: Arthroscopic lateral ankle ligament reconstruction is an effective treatment for chronic ankle instability, with significant improvements in clinical and health-related quality of life outcomes. LEVEL OF EVIDENCE: IV.