Nosocomial urinary tract infection, a common complication in surgical patients, is primarily related to the use of indwelling urinary catheters. Discontinuation of catheter usage within 2 days, whenever possible, is the cornerstone to avoiding these infections. Patients with asymptomatic bacteriuria may be treated with catheter removal only, and do not necessarily require antibiotic therapy. Patients with symptomatic infections should receive effective antimicrobial therapy, but removal of the catheter is also fundamental to clearing the urinary tract of infection. Antibiotic therapy of urinary tract infections is facilitated by the renal concentration of many antibiotics, permitting very high antibiotic concentrations to be achieved in the urine.