AIM AND METHODS: The possibility of using multiplane transoesophageal echocardiography (TEE) and quantitative coronary angiography (QCA) in the diagnostics of stenotic atherosclerosis of the main coronary arteries in a comparative aspect were studied in 94 patients with coronary artery disease (men, mean age 52 +/- 7 years). Coronary arteries stenoses were calculated with Doppler echocardiography using a modified continuity equation: stenosis (%)=100 x(1-prestenotic VTI(d)/stenotic VTI(d)) where prestenotic VTI(d), (cm)=diastolic velocity integral in the prestenotic zone, and stenotic VTI(d), (cm)=in the trans-stenotic zone. RESULTS: High sensitivity and specificity of TEE in the diagnostics of stenotic and occlusive atherosclerosis of coronary arteries were revealed. They measured 88% and 98% for the left main coronary artery (LMCA), 97% and 67% for the left descending artery (LDA), 95% and 92% for the circumflex artery (CX), 83% and 97% for the right coronary artery (RCA), respectively. A high correlation was found between the results of TEE and QCA in the diagnostics of coronary stenoses which were made for the LMCA (r=0.82P 50%) according to a peak diastolic velocity of the coronary blood flow, calculated as 1.4m.s(-1)for the LMCA, 0.9m.s(-1)for the LDA, and 1.1m.s(-1)for the CX. We determined Doppler echocardiography criteria of coronary arteries occlusions such as a 'break' of colour mapping, absence of Doppler spectrum and retrograde blood flow during late diastole. CONCLUSION: Transoesophageal Doppler evaluation of coronary blood flow with application of a modified continuity equation is an accurate, non-invasive method of coronary arteries stenoses diagnostics.