Levels of the fibrinolytic variables, tissue plasminogen activator (tPA) antigen concentration and plasminogen activator inhibitor (PAI-1) activity, were measured in a cross sectional sample of 260 subjects aged 30, 40, 50, or 60 years. There was a significant increase of tPA with age in both sexes, but PAI-1 increased only in women. Linear regression analysis was used to assess relations between tPA or PAI-1 and the anthropometric data. In men, tPA levels were related to body mass index and waist-to-hip ratio, whereas in women, it was also related to systolic and diastolic blood pressures and with abdominal or triceps skinfold thicknesses. PAI-1 levels were related to body mass index and waist-to-hip ratio in men, and in women it was in addition related to systolic and diastolic blood pressures and to abdominal and triceps skinfold thicknesses. These data offer new insight into pathophysiological mechanisms whereby age, sex, blood pressure, and body composition variables such as body mass index or waist-to-hip ratio, might act as cardiovascular risk factors.