Background: Anterolateral impingement associated with intra-articular synovitis, scarring, and fibrosis is a less recognized feature in patients with chronic lateral ankle instability. The aim of our study was to ascertain the incidence of intra-articular synovitis, osteochondral lesions (OCLs), impingement lesions (both intra- and extra-articular), and other associated pathologies in patients undergoing modified Broström-Gould ankle ligament reconstruction. Methods: We performed a retrospective review of all patients who underwent arthroscopically assisted modified Broström-Gould ankle ligament reconstruction for symptomatic recurrent ankle instability. Patients who had previous ankle surgery or inflammatory arthropathy were excluded. Ankle arthroscopy was performed prior to reconstruction in all patients. Data were obtained from clinical and radiological records including magnetic resonance imaging scans. Arthroscopic findings were recorded in detail intraoperatively. A total of 100 patients (53 females and 47 males) with an average age of 37 years (range, 15-65 years) were reviewed over a 10-year period. Results: Sixty-three patients (63%) had intra-articular synovitis mostly in the anterior and/or anterolateral compartment, which required arthroscopic debridement. Seventeen patients (17%) were found to have OCLs, and 12 (12%) patients had anterior bony impingement lesions. Conclusion: This study found a high incidence of anterior/anterolateral synovitis in patients with chronic lateral ankle instability. However, there was a relatively low incidence of anterior bony impingement lesions or OCLs in our series. Level of Evidence: Level IV, retrospective case series.