INTRODUCTION: The purpose of this study was to determine the effect of prophylactic ankle bracing on the incidence of ankle injuries in a high school population of interscholastic volleyball players followed prospectively for one season. MATERIALS AND METHODS: The study was designed to evaluate the effect of different types of ankle braces on the incidence of ankle sprains in high school volleyball players. There were 957 players in the group that wore braces and 42 in the control group who did not wear a brace. Information was collected on age, sex, previous injury, incidence of injury, and time off from play. Only the dominant ankle was studied. RESULTS: Overall, the use of a prophylactic ankle brace did not significantly alter the incidence of ankle sprains in high school volleyball players. However, in players without a previous ankle sprain, the use of an ankle brace did make a significant difference in two of the braced groups. The Active Ankle Trainer II and the Aircast Sports Stirrup protected volleyball players from a sprain only if they had not had a previous sprain. If the player had a history of a previous ankle sprain, these two brace groups did not protect the ankle from another ankle sprain (p < 0.05). In addition, there were significantly more injuries in the female group of players who wore a non-rigid brace versus those who wore a more rigid brace. CONCLUSION: This information may be helpful in deciding whether to recommend prophylactic ankle braces in volleyball players.