Bacterial urinary tract infection rarely is the initial cause of lower urinary tract disease in cats; however, a substantial number of cats with various lower urinary tract disorders develop urinary infections as a complication of the underlying disease or its treatment. Examination of urine sediment for pyuria is a good screening test for urinary tract infection, but results of urine cultures are needed to diagnose such infections reliably, as well as to guide therapeutic decisions. Appropriate antimicrobial drug therapy is the cornerstone of treatment for urinary tract infection. Treatment of the underlying urinary disorder also is important, and follow-up urine cultures should be performed to determine therapeutic outcome.