Introduction The modified Brostrom-Gould procedure is surgery to repair the lateral ligamentous complex of an ankle with chronic instability. A retrospective study was carried out among patients who had undergone this procedure at a medical center. Aim The aim of the study was to determine the mid-term functional outcome and rate of infection among patients who underwent the surgery using the PopLok® (CONMED, NY, US) Knotless Suture Anchor technique for lateral ankle instability. Methods Twenty patients who failed conservative treatment at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Kuala Lumpur, and who were operated on by a single surgeon from January 2011 until March 2015 were selected to participate in this study. They were examined clinically both preoperatively and postoperatively and were also evaluated using the American Foot and Ankle Score (AOFAS) and the Visual Analogue Scale (VAS). The last review of the patients, for the purpose of this study, was done at one-year postoperatively. Results The patients' overall AOFAS and VAS scores improved postoperatively as compared to the preoperative period. Preoperatively, the mean AOFAS score was 63.5 while postoperatively, the score was 93.50 (excellent score 90 - 100). The mean VAS score was 8.00 preoperatively and improved to 1.00 postoperatively. There was also an absence of infection observed one-year post-surgery. Conclusion The modified Brostrom-Gould procedure using the PopLok® Knotless Suture Anchor technique provides an excellent middle-term functional outcome and a reduction in pain for patients who failed conservative treatment, with a very low rate of infection.