The relation of habitual diet and cardiorespiratory fitness to plasma fibrinogen concentration, Factor VII activity (F VIIc), Factor X activity (F X), tissue plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1) concentrations, anti-thrombin III (AT III) and apolipoprotein(a) (Apo[a]) was analyzed in 111 normolipidemic men aged 51-53 years. Diet was evaluated by seven day food records. Maximal oxygen consumption and aerobic threshold were determined in maximal bicycle ergospirometry test based on breath-by-breath analysis of expired respiratory gas. Plasma fibrinogen was measured by thrombin method, F VIIc by one-stage coagulation method, AT III and F X colorimetrically, t-PA and PAI-1 antigens by ELISA and Apo(a) concentration radioimmunologically. Carbohydrate intake was negatively (r = -0.31, p < 0.001; r = -0.24, p < 0.01; r = -0.36, p < 0.001) and fat intake positively (r = 0.24, p < 0.01; r = 0.29, p < 0.001; r = 0.32, p < 0.001) related to F X, PAI-1, and t-PA, respectively. Aerobic threshold correlated negatively with fibrinogen (r = -0.33, p < 0.001) and F X (r = -0.30, p < 0.001). Fasting insulin was the strongest determinant for PAI-1 (r = 0.55, p < 0.001) and a significant positive correlate to F VIIc (r = 0.30, p < 0.001), F X (r = 0.28, p < 0.01) and t-PA (r = 0.47, p < 0.001). These data emphasize the importance that carbohydrate rich diet and cardiorespiratory fitness may have against thrombogenesis.