Objective: To examine the injury rates for boys and girls high school basketball players. Study Design: Prospective cohort. Setting: Seven Indiana high schools during the 2004-05 basketball season. Participants: 160 male and 129 female athletes from rosters of the freshmen, junior varsity, and varsity basketball teams. Main Outcome Measurements: Coaches and Certified Athletic Trainers maintained the Daily Injury Report and documented the number of athletic exposures, injuries, and time lost due to injury. Results: The total number of injuries was 128 for an overall injury rate of 6.4/1,000 AEs. Girls had a significantly higher overall injury rate than boys. Girls were 1.5 times more likely than boys to sustain an initial injury, and two times more likely to sustain a subsequent injury. Conclusions: This study found greater injury rates than other studies. Previous studies may have underestimated injury rates in high school basketball due to lack of accurate exposure data, incomplete or inaccurate injury reporting, or missed time loss injuries that could have been captured by an end of season questionnaire. Our study supports previous work that girls have higher injury rates than boys. Further, this study highlights the need for consistent reporting of injury data.