The term urinary tract infection encompasses a broad range of clinical entities, each with its own pathology and each requiring its own form of treatment. There are at least four different modes in which antimicrobial therapy may be prescribed for urinary tract infection: single-dose therapy aimed at patients with superficial mucosal infection; a conventional seven- to 14-day course of therapy; a prolonged four- to six-week course of therapy for patients with deep tissue infection; and low-dose prophylactic therapy. Increasingly, the response to single-dose therapy is being utilized to delineate the mode of therapy needed by a patient. Patients with underlying renal disease and/or structural abnormalities of the urinary tract are prone to the development of recurrent urinary tract infection, frequently with bacteria resistant to antimicrobial agents conventionally employed to treat the infection. There has been a steady increase, even among otherwise normal persons with urinary tract infection, in the level of antimicrobial resistance exhibited by bacterial uropathogens to the drugs commonly used to treat these infections. The quinolones in general, and ciprofloxacin in particular, appear to be very promising for the treatment of urinary tract infection. It will be important to evaluate the performance of this drug in the four different therapeutic modes and in patients with renal dysfunction or anatomic abnormalities of the urinary tract.