Issuing from the physical principles of the ultrasound technique and the explanation of the different investigation methods, the possibilities of the ultrasonic diagnosis are demonstrated on own results in 1,166 cases of struma nodosa and 154 palpatorically and radiologically, respectively, localised enlargements of the organs or demands of space in the abdominal region. The establishment of 46 cysts in 357 scintigraphically warm nodes of the thyroid gland allows the conclusion that a relatively high percentage of the warm nodes contains solid cold regions. In several cases the ultrasonic diagnosis makes a clear diagnosis, in other cases it is an important supplementation to the other diagnostic possibilities. The A-picture-apparatuses produced in the GDR are suitable for the differential diagnosis of palpatorically or radiologically localised enlargements of the organs or space demands. In diffuse diseases of the organs and for the search of disturbances in extended regions B-picture-apparatuses with improved resolving power are necessary.