Thirty-eight young adults with chronic ankle instability (CAI) were randomized to receive neuromuscular electrical stimulation (NMES) on the peroneus longus muscle (n = 19) or a placebo intervention (n = 19) for 20 minutes, three times per week, over six weeks. The primary outcome was balance control ability, assessed using the center of pressure (COP) trajectory during static single-leg stance. Secondary outcomes included Cumberland Ankle Instability Tool (CAIT) scores, COP displacement in medial-lateral (ML) and anterior-posterior (AP) directions, 95% confidence ellipse area (95%AREA), root-mean-square (RMS), and mean displacement velocity (MV). Outcomes were assessed at baseline and after six weeks. Overall, the results revealed significant improvements in balance parameters and CAIT scores in the NMES group compared to the control group. The findings suggest that NMES enhances balance control, particularly stability in the ankle frontal plane, making it a viable rehabilitation strategy for CAI.