A study was made of the clinical application of diuretic renosongraphy in patients with ureteral trauma. The test comprised an initial renal sonography followed by oral intake of 1000 ml of water and intravenous intake of 40 mg of furosemide; further renosonography was carried out from 5 to 60 minustes later. Four ureteral trauma patients were included in this study. The results were compared with those of standard renosonogrphy and intravenous pyelography. They indicate that the technique is of considerable value. It can make the vital distinction between dilatation due to atonicity on the standard renosonography or intravenous pyelography and that caused by genuine ureteral obstruction.