Based on experience with the examination of 78 children under one year with coarctation of the aorta the authors present an account of basic echocardiographic examination procedures and findings in this defect. Two-dimensional echocardiography revealed in 98.8% of the patients a reduced pulsation of the abdominal aorta, as compared with the pulsation of the ascending aorta. In all instances it proved possible to visualize the coarctation. Pulsed Doppler echocardiography proved an abnormal flow in the abdominal aorta in 89.7% children; at the site of coarctation in 96.1% a typical saw-like flow with an acceleration typical for the flow in a stenotic vessel. Hypoplasia of the aortal arch was recorded in 51.3%, a patent ductus arteriosus in 73.2% of the children. An anomaly of the aortal valve was found in 57.7%, obstruction of the left ventricular, outflow tract in 35.9% children. An anomaly of the mitral valve was present in 23.2% children. M-mode echocardiographic findings proved enlargement of the right ventricle and hypertrophy of its wall. The size of the left ventricle and thickness of its wall differed less from normal values. The width of the aortal root was smaller than in a group of normal patients, the left atrium was enlarged. A combination of echocardiographic methods makes reliable non-invasive diagnosis of coarctation of the aorta in neonates and infants possible, as well as the evaluation of associated defects and indication for operation without the application of invasive methods.