Echocardiographic suprasternal relationships of the transverse aortic arch (TAA), right pulmonary artery (RPA) and left atrium (Y' LAD) were validated and angiographic-echocardiographic measurement correlations were made for each structure. Normal values were determined with respect to body surface area. In normals, regardless of age or body size, mean dimensional TAA/RPA ratio was 1.2:1 and Y' LAD equaled the anterior-posterior, or Z axis, left atrial dimension (Z LAD)- TAA/RPA ratio was increased in aortic stenosis and tetralogy of Fallot and was decreased in ventricular septal defect, atrial septal defect and pulmonary stenosis. Ratio did not correlate with lesions severity as assessed by cardiac catheterization except in pulmonary stenosis. Discrepant Y' LAD values (usually increased Y' LAD and decreased Z LAD) occurred in children with various forms of heart disease. Some had sternal compression but others had normal chests. Children with pectus excavatum showed similar compression. These findings underscore the need for incorporation of a suprasternal examination into the standard echocardiographic examination of children.