Long-term low dose antimicrobial prophylaxis is effective for the prevention of recurrent uncomplicated urinary infections in women. The fluoroquinolone antimicrobials, including norfloxacin, have an in vitro spectrum effective for most uropathogens, and generally achieve high concentrations in the urine. In addition, they are effective for eradication of aerobic Gram-negative flora from the gut. These features suggest these antimicrobials should be effective agents for antimicrobial prophylaxis for urinary infection. Only norfloxacin has been studied in clinical trials to date. In two of the three studies reported, norfloxacin was effective for prophylaxis compared to placebo. In the third study, it was as effective as nitrofurantoin macrocrystals. Infections which occurred during prophylaxis were with organisms resistant to norfloxacin, particularly Enterococcus faecalis and Pseudomonas aeruginosa. Norfloxacin is effective for the prevention of recurrent uncomplicated urinary infections in women. Further studies comparing it to standard regimens are required to identify its specific niche in the management of this common problem.