In the general population, an estimated one in 3000 individuals sustains an anterior cruciate ligament injury per year in the United States, corresponding to an overall injury rate of approximately 100,000 injuries annually. This national estimate is low for women because anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men participating in the same sports, presenting a sizable health problem. With the growing participation of women in athletics and the debilitating nature of anterior cruciate ligament injuries, a better understanding of mechanisms of injury in women sustaining anterior cruciate ligament injuries is essential. Published studies strongly support noncontact mechanisms for anterior cruciate ligament tears in women, which make these injuries even more perplexing. Speculation on the possible etiology of anterior cruciate ligament injuries in women has centered on anatomic differences, joint laxity, hormones, and training techniques. Investigators have not agreed on causal factors for this injury, but they have started to profile the type of athlete who is at risk. In the current study the most recent scientific studies of intrinsic and extrinsic risk factors thought to be contributing to the high rate of female anterior cruciate ligament injuries will be reviewed, important differences will be highlighted, and recommendations proposed to alleviate or minimize these risk factors among female athletes will be reported where appropriate.