The fluoroquinolones are a new, potent class of antimicrobials which are heavily prescribed in the United States. Resistance to these agents has developed primarily in organisms that are inherently less sensitive, such as Staphylococcus spp. and Pseudomonas spp., but also, in some centres, in more sensitive organisms, such as members of the Enterobacteriaceae. Because the fluoroquinolones are a valuable class of broad-spectrum antibiotics, it is desirable that their usefulness be conserved by adopting measures to prevent or minimize the development of resistance. One obvious approach to this is to restrict their use, preventing overuse or misuse. The therapy of urinary tract infections is a major area in which fluoroquinolone usage could be reduced or rationalized. Although these agents are highly efficacious in the therapy of urinary tract infections, so too are older, less expensive agents such as nitrofurantoin, co-trimoxazole, sulphonamides and amoxycillin. From considerations of both economy and minimizing the development of resistance there appears to be little justification for using fluoroquinolones routinely to treat urinary tract infections, except where other oral agents may not be well tolerated or are unlikely to be effective.