Animal models are commonly used for translational research despite evidence that the methodology of these studies is often inconsistent and substandard. This study describes the characteristics and impact of published research using animal models in the American Journal of Sports Medicine (AJSM). Peer-reviewed articles published in the AJSM between January 1990 and January 2010 using animal models were identified using MEDLINE. The articles were reviewed for funding source, anesthesia used, animal used, study type, study location, outcome measures, number of animals, duration of animal survival, main topic being studied, and positive or negative treatment effect. The impact factor of the studies published between 2005 and 2010 was calculated. Two hundred fifty-seven articles, or 6% (257/4278) of the total publications during the 20-year period, were analyzed. The impact factor increased from 1.83 in 2005 to 3.9 in 2010. The most common animals used were rabbits (24%) and pigs (16%). The anterior cruciate ligament was studied in 34% of the articles, and a pig model was used for 31% of these studies. Eighty-six percent of the studies had a positive treatment effect. This study shows that animal models used in sports medicine research lack uniformity in their methods and suggests that a publication bias may exist for animal research in the sports medicine literature.