Given maladaptive neuroplasticity following musculoskeletal injury, interventions capable of restoring corticospinal excitability should be considered. We therefore aimed to determine if 4-weeks of anodal transcranial direct current stimulation (aTDCS) with eccentric exercise would improve neural excitability, functional performance, and patient-reported function in individuals with chronic ankle instability (CAI).Twenty-six individuals with CAI were recruited to undergo 4-weeks of eccentric evertor strengthening. Subjects were randomized into aTDCS (n=13) and sham (n=13) groups, where the aTDCS group received 18-minutes of aTDCS (1.5mA) over the primary motor cortex. Participants were assessed for cortical excitability, dynamic balance & muscle activation, functional performance & strength, and patient-reported function at baseline, week-2, week-4, and week-6.Twenty-two subjects completed the training and test sessions. Cortical excitability (resting motor threshold) to peroneus longus in aTDCS increased from baseline (36.92±11.53) to week-6 (32.91±12.33, p=0.024), while sham increased excitability from baseline (36.67±12.74) to week-2 (27.86±14.69, p=0.007), but decreased at week-4 (35.63±13.10, p=0.022) & week-6 (35.99±13.52, p=0.006). Dynamic balance and muscle activation also improved in the aTDCS group from baseline to week-6 (p=0.034). Functional performance on a side-hop test increased in all participants from baseline to week-2 (p=0.003). The aTDCS group had decreased perceived disablement from week-2 (18.09±6.41) to week-4 (15.55±4.82, p=0.046), whereas the sham group reported increased disablement from baseline (17.91±4.59) to week-2 (21.00±8.52, p=0.047).Our results provide preliminary evidence that 4-weeks of eccentric training with aTDCS improves cortical excitability, functional performance, and patient-reported function in individuals with CAI. These data are the first to show the efficacy of non-invasive brain stimulation therapies in patients with musculoskeletal injury, and demonstrates the link between improved neural excitability and functional outcomes.