Principal component analysis was applied, for the assessment of vital age (more frequently termed the biological age), to the data for 34 physiologic and anthropometric variables. Subjects were 106 Japanese women, aged 30 to 72 years, who were recruited in a series of tests for cardiorespiratory, physical fitness, anthropometric, body composition, and blood lipid profiles.The subjects were categorized into two groups-those (n=15) who possessed either four or more of the coronary heart disease (CHD) risk factors ((1) obesity, (2) hypercholesterolemia, (3) hypertension, (4) low maximal aerobic power, (5) an abnormal electrocardiogram reflecting ischemic patterns, and (6) real sedentary life) including 7 CHD patients and those (n=83) who were considered apparently healthy without CHD risk factors. Analyses of the data revealed that, out of the 34 variables examined, 11 variables were suitable for the assessment of vital age,and that the individuals with many CHD risk factors were approximately 7 years older when compared to their chronological ages (54.6 ± 9.9 vs. 61.4 ± 7.2 yr). Healthy individuals were,however, found to have similar vital ages (49.1 ± 11.0 yr). to their chronological ages (49.0 ± 8.9 yr). The developed equation for the estimation of vital age (VA) was VA=8.90VS+49.0+Z,VS=-1.035 +0.016X_1 +0.011X_2 -0.064X_3 -0.012X_4 +0.004X_5 +0.004X_6 +0.004X_7 +0.034X_8 -0.037X_9 -0.005X_<10> -0.367X_<11>, Z=0.33Age -16.17; where X_1=abdominal girth (cm), X_2=SBP (mmHg), X_3=VO_<2LT> (ml/Kg/min), X_4=HR_<LT> (b/min), X_5=TC (mg/dl), X_6=LDLC (mg/dl), X_7=TG (mg/dl), X_8=hematocrit (%), X_9=side step, X_<10>=one-leg balance with eyes closed(s), and X_<11>=FEV_<1.0^s>(l). Since independent variables of this equation included physical fitness items and those measured during submaximal exercise stress test, we defined the score obtained from the equation as "vital age." Importance and usefulness of the vital age were discussed.