The study describes the technique and standardized evaluation of suprasternal M-mode echocardiography. The day-to-day variability of suprasternal echoparameters was tested in 7 subjects studied on five consecutive days. The variation coefficient found ranged from 3.5 to 6%. The interobserver variability were tested by evaluation of 127 suprasternal echocardiograms from two investigators independently. Absolute values differed slightly in only 2 out of 8 parameters between both investigators by about 0.8 and 6.3%. 349 consecutive patients were subsequently studied with the suprasternal notch technique. The clinical diagnosis of these patients were as follows: 35 normal subjects, 122 patients with coronary heart disease, 155 patients with valvular heart disease, 33 patients with dilative and 4 with hypertrophic cardiomyopathy. The feasibility to record the aortic arch amounted to 68%, the right pulmonary artery was visualized in 85%, and the left atrium was seen in 75% of the patients studied. The echographic parameters correlated to body size, weight and body surface area. It could be demonstrated that also hemodynamic changes caused variations of these echographic parameters. The different clinical entities did not differ from each other with respect to these suprasternal echoparameters for those in whom the pulmonary artery pressure was within normal range. The size of the pulmonary artery and of the left atrium was found increased in those patients with an elevated pulmonary artery pressure. The suprasternal approach seems to be a useful completion of the echocardiographic technique and should be applied routinely.