Background Deficiencies in ankle proprioception and standing balance in basketball players with multiple ankle sprains have been reported in separate studies. However, the question of how ankle proprioceptive inputs and postural control in stance are related is still unclear. Hypothesis Ankle repositioning errors and the amount of postural sway in stance are increased in basketball players with multiple ankle sprains. Study Design Controlled laboratory study. Methods Twenty healthy male basketball players and 19 male basketball players who had suffered bilateral ankle sprains within the past 2 years were examined. Both groups were similar in age. Passive ankle joint repositioning errors at 5° of plantar flexion were used to test for ankle joint proprioception. The Sensory Organization Test was applied with dynamic posturography to assess postural sway angle under 6 sensory conditions. Results A significant increase in ankle repositioning errors was demonstrated in basketball players with bilateral ankle sprains (P < .05). The mean errors in the right and left ankles were increased from 1.0° (standard deviation, 0.4°) and 0.8° (standard deviation, 0.2°), respectively, in the healthy players to 1.4° (standard deviation, 0.7°) and 1.1° (standard deviation, 0.5°) in the injured group. A significant increase in the amount of postural sway in the injured subjects was also found in conditions 1, 2, and 5 of the Sensory Organization Test (P < .05). Furthermore, there were positive associations between averaged errors in repositioning both ankles and postural sway angles in conditions 1, 2, and 3 of the Sensory Organization Test (r = 0.39-0.54, P < .05). Conclusions Ankle repositioning errors and postural sway in stance increased in basketball players with multiple ankle sprains. A positive relationship was found between these 2 variables. Clinical Relevance Such findings highlight the need for the rehabilitation of patients with multiple ankle sprains to include proprioceptive and balance training.