The principle of vectorcardiography is first discussed. The setting out in space is very instructive. An over-valuation of slight vectorcardiographic changes can lead to wrong conclusions. The changes in right hypertrophy may in many cases be important for diagnosis. This is true for cases of intraventricular conduction disturbance and incomplete right bundle branch block. In certain cases of myocardial infarction, the vectorcardiogram can be valuable as additional diagnostic method. Finally the diagnostic possibilities of vectorcardiography in pacemaker patients, contour irregularities of the vector loops, congenital valvular heart disease and ventricular extrasystole, and the question of standardisation are discussed.