OBJECTIVES: The goals were to calculate injury rates among high school baseball players and to characterize the general epidemiological features of high school baseball injuries and, more specifically, injuries attributed to being hit by a batted ball. METHODS: We analyzed baseball exposure and injury data collected over the 2005-2006 and 2006-2007 school years from a nationally representative sample of 100 US high schools by using an injury surveillance system, Reporting Information Online. RESULTS: Nationally, an estimated 131555 high school baseball-related injuries occurred during the 2005-2006 and 2006-2007 academic years, for an injury rate of 1.26 injuries per 1000 athletic exposures. The most commonly injured body sites were the shoulder (17.6%), ankle (13.6%), head/face (12.3%), hand/finger (8.5%), and thigh/upper leg (8.2%). The most common injury diagnoses were ligament sprains (incomplete tears) (21.0%), muscle strains (incomplete tears) (20.1%), contusions (16.1%), and fractures (14.2%). Although the majority of injuries resulted in a time loss of <7 days, 9.7% resulted in medical disqualification for the season, and 9.4% required surgery. Of the 431 reported baseball injuries, 50 (11.6%) were attributed to being hit by a batted ball. Greater proportions of injuries attributed to being hit by a batted ball were to the head/face (48.0%) and mouth/teeth (16.0%), compared with injuries not attributed to being hit by a batted ball (8.2% and 1.3%, respectively). A greater proportion of injuries attributed to being hit by a batted ball required surgery (18.0%), compared with other baseball-related injuries (6.8%). CONCLUSIONS: Although high school baseball is relatively safe, targeted, evidence-based interventions could reduce the rate of high school baseball-related injuries. On the basis of our findings, we strongly recommend that helmets with face shields or at least mouth guards and eye protection be used by pitchers, infielders, and batters at the high school level.