There is absence of data in international publications, on the measurement of coronary flow in 2nd type diabetes patients (DM) during stress-echocardiography (SEchoCG) with physical exertion (PE). Aim. To study the changes of coronary flow in left anterior descending artery (LAD) during SEchoCG with PE in DM patients with and without signs of coronary heart disease (CHD). Material and methods. Totally, 125 patients included, with good visualization of coronary arteries in transthoracic approach. Main group consisted of 68 DM patients, controls were 57 persons comparable by age and gender, without diabetes and CHD signs. All patients underwent SEchoCG on horizontal veloergometer, with Doppler test of blood flow in LAD. Positive stress test patients underwent then coronary angiography. Results. Between the subgroups with DM and CHD and non-CHD, there was highly significant difference in absolute values of velocities on the peak of PE, of velocity increase during PE, and in coronary reserve (CR) in LAD. DM patients without CHD did not significantly differ by the parameters mentioned, from the controls. Threshold value that determine relation of patients to CHD or non-CHD group, was 1,7 for CR. Test precision for subgroup relevance for this level was 86,2%. Conclusion. DM non-CHD patients during PE do not differ from non-DM by the values of coronary flow. CR parameter can be used for CHD diagnostics during SEchoCG with PE in this category of patients.