Background: The increased physical demands of professional athletes predispose this patient population to a unique set of injuries typically not seen in the general population. This systematic literature review investigates the nature of injury reporting (both orthopedic and nonorthopedic conditions) in the medical literature of professional athletes in the National Football League (NFL), Major League Baseball (MLB), the National Basketball Association (NBA), and the National Hockey League (NHL). Rigorous reporting of sports injuries helps clinicians better understand disease mechanisms relevant to specific sports. Hypothesis: The nature of injury reporting will differ within each professional sport and reflect the anatomic emphasis of each sport. Methods: An electronic literature search of all publications addressing injuries and medical conditions among professional athletes in the NFL, MLB, NBA, and NHL was conducted using the Pubmed/Medline, Scopus, and Embase databases through January 2013. Retrieved publications were categorized by journal type, medical type, and area of focus. Results: A total of 536 publications met all inclusion criteria. There were a higher number of articles regarding the NFL (n = 211) and MLB (n = 216) when compared with the NBA (n = 34) or NHL (n = 75). The NFL had significantly more articles addressing nonorthopedic injuries/medical issues than were found with the MLB, NBA, or NHL (109 vs 75, 14, 41, respectively). Both the NFL (33 of 109, 30%) and NHL (6 of 41, 15%) had a relatively high percentage of articles regarding concussions/neurology, and MLB had a relatively high percentage of articles dedicated to vascular medicine (13 of 65, 20%). The proportion of publications dedicated to the knee/lower leg were highest in the NFL (29 of 102, 28%) and NBA (9 of 20, 45%), those dedicated to the shoulder/elbow were highest in MLB (113 of 151, 75%), and those dedicated to the hip/pelvis were highest in the NHL (16 of 34, 47%). Conclusions: The number and type of publications vary among the 4 professional sports leagues, and generally reflect the nature of the sport being played.