OBJECTIVES To determine the effectiveness of K-tape on dynamic postural stability of the injured limb in adolescent athletes with chronic ankle instability (CAI) by measuring reach distance with the modified Star Excursion Balance Test (mSEBT). METHODS Twenty volunteers (20 females [17.78 ± 1.22 yrs], height [163.89 ± 7.69 cm], mass [62.51 ± 9.81 kg]) with CAI. Four strips of K-tape were applied to the injured limb. Participants completed 4 trials of testing (2 with tape, 2 without tape) using the mSEBT as the assessment tool. We applied 4 strips of K-tape to the injured limb and then tested postural stability using the mSEBT to see if there was an increase of reach distance in the mSEBT. Measuring reach distance in Anterior (AN), Posteromedial (PM), Posterolateral (PL) on the injured limb with K-tape and without K-tape condition. We measured the reach distances and then normalized the distance to account for height differences. A repeated measures t-test was used for this study. RESULTS There is no statistically significant different between the condition with K-tape and without K-tape in the reach distances on the mSEBT in adolescent athletes with CAI. CONCLUSIONS Based on the results, there appears to be no improvement of reach distance using the mSEBT in adolescent athletes with CAI. Therefore, clinicians need their thoughtful consideration for applying K-tape to improve dynamic postural stability in adolescent athletes with CAI.