Bacteriuria remains the most important sign of urinary tract infection. A standardization of the diagnosis and treatment of urinary tract infection requires a standard period of urine collection (4 hours), the correct collection of specimens, the determination of the number of bacteria by appropriate media (dipslide) and of urinary leucocytes. Test strips cannot replace the microscopy of the sediment. The therapeutic consequences result from the localization of the infection, the duration of treatment of cystitis is 1 to 4 days, of pyelonephritis 10 to 14 days.