One of most controversial problems in cardiac muscle pathology is the existence of myocyte hyperplasia. The term hypertrophy indicates an increase in size of the individual muscle cells without changing their total number, whereas in hyperplasia proliferation of the myocyte occurs. This fundamental question of the character of cardiac growth remains unresolved in spite of the wide attention in has received. Contemporary views concerning the cardiac muscle hyperplasia are presented. From clinical point of view the problem is significant for two reasons. The loss of the ability of muscle cells to proliferate is responsible for the irreversible myocardial destruction after injury. From another point of view, if the increase of the heart muscle is maintained, although a complete remission of cardiac hypertrophy becomes impossible. In the light of these controversies we undertook the attempt to solve this complicated problem. Morphometric evaluation of the cardiac myocyte is described in detail.