Retired National Football League (NFL) linemen have higher cardiovascular mortality compared with nonlinemen. We examined echocardiographic characteristics of retired NFL linemen compared with nonlinemen to determine if position-dependent cardiac remodeling resulted in increased left ventricular (LV) mass and left atrial (LA) size. We performed echocardiography in 487 retired NFL football players. Demographic, medical, and professional career information was collected. Interventricular septal and posterior wall thickness, LV end diastolic diameter, and LA area were measured. Body mass index (BMI) and LV mass were calculated. Retired linemen had significantly higher LV mass (234.8 +/- 65.8 g) than nonlinemen (199.8 +/- 55.4 g, p <0.0001). LA area was higher in linemen versus nonlinemen (22.5 vs 20.1 cm(2), p <0.0001). Independent predictors of increased LV mass were BMI (p <0.003), linemen position (p <0.024), and systolic blood pressure (p <0.005). In former players with BMI <35 kg/m(2) there was a difference between linemen and nonlinemen in LV mass (219.9 +/- 44.3 vs 182.6 +/- 44.3 g, p = 0.004) and LV mass/height (114.3 +/- 23.5 vs 98.8 +/- 25.2 g/m, p = 0.005). In former players with BMI >35 kg/m(2), there was no difference. There was no difference in LA area between linemen and nonlinemen in both BMI groups. In conclusion, LV mass and LA area size were highest in retired linemen. Player BMI, position, and systolic blood pressure were significant predictors of LV mass. In retired linemen compared with retired nonlinemen, the persistence of these cardiac adaptations may contribute to the higher cardiovascular mortality seen in retired linemen.