The development of a renal lesion following an adenoma of the vesical neck is one of the most important complications of this disease. For the determination of the frequency of changes of the renal calyces in the adenoma of the vesical neck the findings of 253 patients of the years 1976 and 1977, in whom for the first time such an excrescence was established were evaluated. 135 excretion urogrammes showed changes of the renal pelvis and the renal calyces. The main findings were a narrowing of the renal calyces with spindle-shaped necks of the calyces. The calyces themselves were deformed only in one part of the patients. Urinary stasis and cirrhoses of the kidney were not found. As cause of the narrowed renal calyces in correlation with the clinical and laboratory-clinical findings the chronic pyelonephritis, the latent dehydration of the patient and disturbances of the motility of the urodynamics are discussed. As conclusion of these results the opinion is uttered that all male persons from 45 years, who have clinically healthy kidneys and in whom for any reasons an excretion urography has been performed, and in which evaluation narrowed renal calyces were found, by all means must undergo the examination by an urologist for the exclusion of a disease at the vesical neck.