BACKGROUND: Knowledge of alteration in coronary artery flow during physical activity provides important and valuable information about every patient. AIM: The aim of our study was (a) to identify the possibility of assessing coronary artery flow parameters using different ultrasound systems during the exercise test and (b) to compare these parameters with angiography data. METHODS: A total of 400 consecutive nonselected patients were enrolled. Group 1 included 200 patients who underwent supine exercise echocardiography with the ultrasound system Sonoline G 60S and group 2 included 200 patients who performed the same stress test with the system Vivid 7 Dimension. Before and after exercise, Doppler velocity curves were obtained in the posterior descending coronary artery (PDA) and the left anterior descending artery (LAD). The differences between poststress and rest velocities (ΔV) and the 'poststress velocity/rest velocity' ratio were also calculated. In total, 123 patients underwent a coronary angiography. RESULTS: A total of 92% PDA and 85% LAD before the exercise and 81% PDA and 60% LAD after the exercise were feasible for the assessment of peak velocity in group 1. And a total of 95% PDA and 85% LAD before the exercise and 80% PDA and 57% LAD after the exercise were feasible for group 2. A significant correlation was observed between peak velocities after stress and the percentage of LAD stenosis severity (r-0.60, P<0.0001); between ΔV and LAD stenosis severity (r-0.65, P<0.0001); between the 'poststress velocity/rest velocity' ratio and LAD stenosis severity (r-0.61, P<0.0001); and between peak velocities and percentage of PDA stenosis (r-0.3, P<0.01). The accuracy, sensitivity, and specificity were 80, 90, and 62% for the peak of LAD; -80, 92, and 68% for ΔV of LAD; and 83, 93, and 57% for the 'poststress velocity/rest velocity' ratio, respectively. CONCLUSION: It is feasible to assess coronary artery flow by a transthoracic Doppler during supine exercise. The parameters of Doppler coronary flow velocities correlate significantly with coronary angiographic data.