Abstract:Serial urine cultures were evaluated in 82 patients with noninfectious parenchymal renal disease confirmed by renal biopsy in order to assess the incidence and morbidity of bacteriuria. The mean period of observation was 26 months (6 to 73 months), and mean number of cultures was 17 per patient (2 to 80). Primary diagnoses were glomerulonephritis, arteriolar nephrosclerosis, diabetic glomerulosclerosis and miscellaneous. Bacteriuria was found in 15 patients (18%). Six males (13%) and nine females (24%) comprised this group. Only two (2.4%) acquired bacteriuria for the first time during the study period. All of the males had urinary tract obstruction or immunological deficiency, and some of the females appeared to have only bladder infections. Morbidity associated with bacteriuria was low in a setting in which relief of obstruction and appropriate antimicrobial treatment was given to these patients. A deleterious effect of bacteriuria upon the underlying renal disease could not be documented in any patient. Bacteriuria should not be attributed to the underlying renal disease until appropriate urologic evaluation of the patient has been performed.