Women's participation in intercollegiate athletics has increased dramatically in recent years. Greater par ticipation has increased awareness of health and medical issues specific to the female athlete. Some reports have noted a higher susceptibility to knee in jury, specifically injuries to the anterior cruciate liga ment, in female athletes as compared with their male counterparts. We performed a 5-year evaluation of anterior cruciate ligament injuries in collegiate men's and women's soccer and basketball programs using the National College Athletic Association Injury Sur veillance System. Results showed significantly higher anterior cruciate ligament injury rates in both female sports compared with the male sports. Non contact mechanisms were the primary cause of an terior cruciate ligament injury in both female sports. Possible causative factors for this increase in anterior cruciate ligament injuries among women may be ex trinsic (body movement, muscular strength, shoe- surface interface, and skill level) or intrinsic (joint lax ity, limb alignment, notch dimensions, and ligament size).