Despite introduction to a host of antibiotic and chemotherapeutic agents during the past 25 years, many infections of the urinary tract progress to a chronic stage where eradication of the causative organism is unsuccessful. Aside from the evaluation of therapeutic agents and definition of the cause and consequences of these infections, recent efforts have been in four major directions. The first is prevention of contamination of the bladder. Infection has long been recognized to follow use of the urethral catheter. Yet, the catheter must be used at times, and indications for its use have been categorized. To minimize the frequency of bladder contamination from catheterization, two general methods are employed: meticulous asepsis to prevent access of bacteria, and the rinsing out of bacteria which may have gained access to the bladder by the use of intermittent or continuous irrigation with antibacterial solutions. Another goal is earlier and more accurate diagnosis.