The ultrasonic tomography has been used among other methods to diagnose nonorganic extraperitoneal tumours in 114 patients. The results have shown the ultrasonic tomography to be an efficient method permitting one to diagnose the tumours in 91.4% of cases studied. The high diagnostic accuracy of the method (87.7%), the absence of irradiation load noninvasiveness and economy of ultrasonic tomography make it a useful method for screening extraperitoneal nonorganic tumours at early stages of patients observation.