OBJECTIVE To evaluate frontal and sagittal plane ankle kinematics between subjects with chronic ankle instability (CAI) and healthy controls while walking and jogging shod on a treadmill. METHODS Cross-sectional study. METHODS Motion analysis laboratory. METHODS Fifteen subjects with self-reported CAI and 13 healthy subjects volunteered. METHODS Sagittal and frontal plane ankle kinematics were calculated throughout the gait cycle. For each speed, the means and associated 90% confidence intervals (CIs) were calculated in each plane across the entire gait cycle and increments in which the CI bands for the groups did not cross each other for at least 3 consecutive percentage points of the gait cycle were identified. RESULTS At various increments while both walking and jogging, CAI subjects were found to be more plantar flexed compared to controls. In the frontal plane, CAI subjects were found to be more inverted at three different increments while jogging only. CONCLUSIONS While shod, kinematic differences were observed between groups. The alterations may indicate that while shod, CAI subjects may adjust their gait in order to successfully accomplish the given task.