The experience in using radiolymphography in the diagnosis of central lymph dynamics disorders in thoracic duct pathology has been analysed. For the first time in Soviet literature we encounter two observations over the state of lymph dynamics along the thoracic duct by means of lymphoscintigraphy with colloid 113mIn in patients with lymphangiectasia of the thoracic duct and chylothorax. In importance of lymphoscintigraphy in determining the compensatory mechanisms of the lymph flow in primary pathology of the main lymph collector is emphasized.