The purpose of this study is to document the epidemiology of Achilles tendon ruptures in the National Football League (NFL) and to quantify the impact of these injuries on player performance. A retrospective review of several online NFL player registries identified 31 Achilles tendon ruptures in NFL players between 1997 and 2002. Nineteen percent of injuries occurred during preseason play, while another 18% occurred during the first month of the official season. There was a postinjury reduction of 88%, 83%, and 78% in power ratings for wide receivers, running backs, and tight ends, respectively, over a 3-year period. There was a 95%, 87%, and 64% postinjury reduction in power ratings for linebackers, cornerbacks, and defensive tackles over a 3-year period. On average, players experienced a greater than 50% reduction in their power ratings following such an injury. Thirty-two percent (n = 10) of NFL players who sustained an Achilles tendon rupture did not return to play in the NFL.