One hundred eighty consecutive male patients, mean age of 64.6 years, who were referred to cardiac catheterization for the evaluation of aortic stenosis (AS), were studied using a noninvasive scoring system. The system is based upon 7 variables including: 1) LVH by ECG, 2) aortic valve calcium by chest x-ray, 3) loud ness of A2, 4) Q to peak of murmur, 5) T time of the carotid pulse, 6) LV ejection time and 7) LVH by echocardiography. The scoring system has a range from 0 to 16, and a score≧5 indicates severe AS (valve area ≦ 1.0 cm2). Eighteen patients had hemodynamic studies on two occasions. In 3 years progression of stenosis was evident by an increase in the mean aortic valve gradient from 23±3.4 mmHg to 44±4.2 mmHg (p<0.005).The aortic valve area decreased from 1.4±0.1 cm2 to 0.76±0.07 cm2 (p<0.005). Noninvasive scores increased in these patients from 2.1±0.5 to 7.6±1.0 (p<0.005). Fifty-one patients had repeated noninvasive studies. Twenty-two patients, who had mild AS at the initial evaluation, attained a score of ≧5 in 3 years, indicating probable progression to severe AS. The mean initial score was 2.3±0.4, and the score at the end of the mean follow-up period of 3 years was 8.0± 0.6 (p<0.005). It is concluded that progression of AS over a 3-year period in the elderly patients occurs frequently and progression can be estimated noninvasively.