Investigations, performed in organ complexes of neck and mediastinum in 50 corpses of adults, demonstrated, that all cervical cardiac nerves and cardiac branches of vagal nerves are united into a single plexus, branches of which form the nerves, approaching the heart. Some of them are formed under the aortal arch and behind the brachiocephalic trunk. They are located on the ascending aorta and on the pulmonary trunk, approaching the coronary sulcus of the heart, participating in the innervation of all its regions. Other preorgan cardiac nerves are formed under the pulmonary arteries, approach the atria, ramifying in their walls and also participating in the forming the subepicardial plexuses, innervating diaphragmal surfaces of the heart ventricles.