The present case series study was performed to evaluate the effect of obesity on the arthroscopic findings and the functional outcome after arthroscopic treatment of anterolateral impingement syndrome of the ankle. The study was conducted on 36 patients (26 were classified as obese [body mass index ≥30 kg/m2] and 10 as not obese [body mass index <25 kg/m2]) who had previously undergone arthroscopic treatment of anterolateral impingement syndrome of the ankle. The arthroscopic findings and demographic features were recorded. The patients were examined postoperatively at 6 and 12 months postoperatively, and AOFAS scores were obtained. Our data showed that obese patients had the same arthroscopic findings as nonobese patients, except for chondral lesions. At 1 year of follow-up after performing arthroscopy, the presence of obesity had no effect on the functional outcome of arthroscopic treatment of anterolateral impingement syndrome of the ankle.Obesity has no effect on the effectiveness of arthroscopic treatment.