[en] The diagnostic efficacy of ultrasonic location of the kidneys in combination with radionuclide renography (iodine-131) is studied. Examinations of 49 patients with different status of the urinary system are carried out. Conventional renography (with preliminary determination of the renal topography) was followed by ultrasonic location of the kidneys before renography notably improved the accuracy of evaluation of the kidney function and status of the upper urinary tract. Ultrasonic location of the kidneys is suggested to be carried out before renography. Replacement of X-ray topometry by sono-location reduces ionizing radiation dose to patient. In addition, ultrasonic topometry is a simple noninvasive cheap method promoting high accuracy when determining functional state of kidneys