Researches effected in different nations have revealed that 5-12% of all hospitalized patients was affected with a nosocomial infection and that almost 1/3 of these were urinary tract infections. The hospitalized urological patients have a considerable proneness to contract a nosocomial urinary tract infection, because they are subjected to transurethral or suprapubic bladder catheterisms, to transurethral surgery and to the endoscopies, that are promoting maneuvers the urinary tract infections. Generally the Gram negative bacilli are the cause of hospital-acquired urinary tract infections, even if lately Gram positive bacilli (especially Streptococcus Faecalis or Enterococcus), "Gram negative Facultative pathogens" (Klebsiella, Providencia, Citrobacter, Serratia) and Fungi are very important. Considering the importance of these infections we have examined the incidence of the urinary tract infections of the hospitalized patients between January 1, 1986 and December 31, 1986 in our Urologic Institute. During the 12-month study interval there were 450 hospital admissions, and 45 patients were affected with a nosocomial urinary tract infection (10%). The females were affected at the rate of 6.7% of them, with an incidence of 4.7% among all patients with a positive urine culture; on the contrary the males were affected at the rate of 11.4% of them, equal to 19.0% of patients with a positive urine culture. We have noticed that among the responsible microorganisms for the nosocomial urinary tract infections, the group of the "Gram negative Facultative pathogens" was more frequent (40%), followed by Pseudomonas Aeruginosa and Candida species. So also in our Urologic Institute the modification of the responsible agents for the nosocomial urinary tract infections happened. The nosocomial infections after the discovery of the antibiotics were considered wiped out, on the contrary these infections are still an important problem of public health, so that efficaciously must be tackled.