The heart is a special muscle whose work can be described as two interconnected pumps. One pumps blood through the lungs while the other through the whole body to the other tissues. The average weight of the heart is 200-450g and during life it makes 3.5 billion beats, which would mean 100 000 per day. In newborns, the most common group of congenital defects are problems and defects of the heart, which we call heart defects. Out of 1000 newborn children, 6-7 will have some of the heart defects. We can recognize heart defects most often by the children’s bluishness, shortness of breath, loss of consciousness, heart murmurs. Heart defects are divided into defects that cause cyanosis, i.e. blueness of the child and we call them cyanotic heart defects and another group of non-cyanotic defects that do not cause cyanosis. The occurrence of heart defects is mostly due to genetic predisposition or genetic inheritance and due to some other influences which are mainly related to exposure to teratogens during pregnancy. Midwives, who continuously monitor the health of the newborn, play an important role in the diagnosis of heart defects. When assessing the condition of the newborn, the midwife must pay attention to the ease and speed of breathing, irregularities such as pronounced tremors, convulsions and unbalanced nutrition, and if she notices them, she has to inform the neonatologist. Research has proven that heart defects are the most common cause of death in the prenatal and early neonatal age.