This study examined progression of aortic stenosis (AS) as assessed by Doppler echocardiography. One hundred twelve consecutive adult patients had calcific AS and underwent three examinations during a mean 25-month period (range 7 to 54 months). At the time of entry into the study, mean values for initial peak aortic velocity and ejection fraction (EF) were 2.9 +/- 0.7 m/sec and 63 +/- 10%, respectively; 52% of the patients were symptomatic. At the third examination the percentage of symptomatic patients increased to 65% (p = 0.0039 compared to baseline values), and the aortic peak velocity increased to 3.3 +/- 0.8 m/sec (p less than 0.001). Age, sex, and EF were not predictors of progression. Documented coronary artery disease (in 57 patients) did not affect progression, and neither did the aortic peak velocity at the time of entry into the study. Thirty-eight patients reported an increase in symptoms from the first to third examination, and their rate of progression was significantly different from that of the rest of the population: 0.33 +/- 0.50 m/sec/yr compared to 0.18 +/- 0.26 m/sec/yr (p less than 0.03).