The technique and the state of efficacy of the ultrasonic diagnosis diseases of the bladder and the kidneys are represented in consideration of literature and own experiences by means of numerous pictures. In the bladder diseases the sonographic results of examinations are described in acute and chronic cystitis, in the presence of urinary gravel, urinary culculus and uroncus. Above all the aspects concerning differential diagnoses are featured in the examination and findings. After representation of physiological ultrasonic pictures of the kidney alterations of the parenchym of renal pelvis, renal medulla and renal cortex as well as cystic und tumorous alterations of the kidney are represented. In small animal veterinary medicine sonography gets more and more importance. The owner of an animal lays claim to a diagnosis of bladder- and kidney-diseases possibly extended by an ultrasonic examination to be prognostically advised after concerning differential diagnoses clarification of the disease.