In 50 right and 50 left upper extremities examined in adult persons of both sex at the age of 28-90 years, delto-thoracic lymph nodes were revealed in 30% (right) and in 22% (left), and interthoracic lymph nodes--in 6% (right) and in 12% (left). The lymph nodes in question were revealed by the method of section after interstitial injection of Gerota's blue intradermally to fingers, palm, back of the hand deltoid area, lateral thoracic surface (at the level of the 6th intercostal space) and to the external part of the mammary gland. Injection was also performed into lymphatic vessels revealed by means of the interstitial injection. The delto-thoracic nodes were stated to situate in both the delto-thoracic sulcus and the delto-thoracic triangle. These vessels are situated along the course of the lateral collector of the free upper extremity. Deferent vessels of the delto-thoracic nodes flow into the apical axillary lymph nodes, into the deep and superficial cervical nodes, into the interthoracic lymph nodes and also into the subclavicular or into the jugular vein near a corresponding venous angle. Interthoracic lymph nodes, situated between musculus pectoralis major and minor, get their lymphatic vessels from lateral, inferior and central axillary nodes, from delto-thoracic nodes and also those lymphatic vessels that go from the mammary gland area. Deferent vessels of the interthoracic nodes flow into the apical axillary nodes.