For the characterization of the left-ventricular thickness of the wall, of the diameter and of the functional parameters in obesity in a short-term investigation on 18 extremely adipose female normotonics and 17 normotonics with normal weight the echocardiographic investigation in the M-mode in the short parasternal axis was performed. The women with overweight had a by 28% (p less than 0.001) greater fractional shortening, a by 8% (p less than 0.01) greater ejection fraction, a by 23% (p less than 0.05) greater stroke volume and a by 34% (p less than 0.001) greater cardiac output as well as a by 13% smaller left-ventricular end-systolic volume than normotonic women with normal weight. Index of stroke volume and cardiac output did not differ. The women with overweight had a significantly larger left-ventricular end-diastolic diameter and a thicker interventricular septum as well as a larger thickness of the left-ventricular posterior wall in the systole. The results allowed the conclusion that changed left-ventricular parameters both with regard to the form and to the function in obesity per se might be the expression of the physiological adaptation to an increased requirement and the borderlines to the transition into a disturbed left-ventricular function and development of a left-ventricular hypertrophy were not fixed. Long-term studies should bring further explanation concerning these problems.