Common respiratory diagnostic imaging techniques using radioisotopes are ventilation-perfusion, perfusion, aerosol inhalation and tumor scintigraphy. The special features of respiratory imaging diagnostic techniques using radioisotopes are the possibility of early detection of disease and the non-invasiveness of the procedure. Also, no patient effort is required. The kinds of isotopes used are as follows: ventilation-perfusion (133Xe, 13N, 99mTc-pseudogas), perfusion (131I, 99mTc), aerosol inhalation (99mTc), tumor (67Ga, 201Tl). The advantages of these procedures are expected to lead to further developments in respiratory examinations using radio isotopes.