M-mode echocardiographic study was made of eight healthy patients scheduled for extrathoracic surgery to determine wheter this technic could be used in the operating room and to evaluate the effect of the induction procedure, commonly used in our department, on left ventricular performance. Ventricular minor-axis dimensions were measured by echocardiography at end-systole and end-diastole. Cardiac pump function was evaluated by determination of the left ventricular volumes and ejection fraction from the echocardiographic dimentions using formulae. Measurement of arterial pressure, left ventricular ejection fraction, left ventricular fractional shortening and mean velocity of circumferential fiber shortening were not changed significantly, while increasing the heart rate was statistically significant. These data indicate that our commonly used induction technic was a safe method in healthy adults by the echocardiographic measurement. Echocardiography is a non-invasive method without known risk, painless, easily repeatable and relatively rapid so can be used in the perioperative period to assess cardiac function and to evaluate the effects of pharmacologic agents on the heart. The observations reported here demonstrate the validity of echocardiography and ist usefulness in mornitoring changes of left ventricular function during the induction period of anesthesia.