A new technique of urinary tracts visualization--magnetoresonance urography (MRU)--for a year (2000) was applied in examination of 25 patients aged 17 to 63 years with ureteral concrements (n = 11), ureteropelvic stenosis (n = 10), ureteral stenosis (n = 2), urinary bladder tumor (n = 1), Ormond's disease (n = 1). MRU provides the same information about the obstruction and dilatation of the urinary tracts as excretory urography (EU). In cases of EU contraindication (allergy, renal failure) or lack of contrast substance excretion, MRU allows to avoid additional invasive diagnostic procedures. It also enables visualization of non-dilated urinary tracts in medicinal polyuria. Non-invasiveness, no need to contrast, absence of radiation load open wide perspectives for MRU application in various groups of patients including pregnant women.