The article is dedicated to the early organogenesis of the heart at 4—8 weeks of embryogenesis. The characteristics of the formation and development of the venous sinus, interatrial and interventricular septa, atrial wall, septa in the atrioventricular canal, arterial trunk and cone, the formation of atrioventricular and semilunar valves at the early stages of embryonic development are presented. The developmental and formation variations of defects of interatrial and interventricular septa and anomalies of the structures referred to above are described. The study of organogenesis of the heart promotes to determine the mechanisms of heart congenital malformation development, to detect morphological base of heart diseases development.