Infusion urography and ultrasound examinations were performed in 54 patients in order to diagnose renal stones. The patients were examined because of upper abdominal pain, suspected renal calculi or for follow-up of known calculi. In 20 patients, stones could be demonstrated by both methods. In four patients, radiological suspicion of the presence of stones was not confirmed by ultrasound. In two patients ultrasound produced false positives and in seven patients renal stones were demonstrated only by sonography. These results were obtained with a mechanical sector scanner. The advantages and disadvantages of compound and of real-time-scanners and their place in the diagnosis of kidney stones are discussed.