Short-term therapy, including single-dose treatment and up to 3-day courses, can be considered the treatment of choice in premenopausal women with acute uncomplicated cystitis, because of similar effectiveness, better tolerance and compliance, and lower cost as compared with conventional therapy. Several studies with trimethoprim alone or in combination with a sulfonamide, usually sulphamethoxazole, and with fluoroquinolones with moderately long half-lives, such as ciprofloxacin, enoxacin, lomefloxacin and ofloxacin, suggested that results obtained with a single dose may be inferior to those with a 3-day course, and therefore that the latter may be better. Longer therapy was not considered to be necessary. On the other hand, fluoroquinolones with longer half-lives, such as fleroxacin, pefloxacin and rufloxacin, as single-dose therapy may be as effective as other standard regimens. Fosfomycin trometamol may also be suitable for single-dose therapy. Agents that have not been shown effective in any of these short-term regimens should no longer be used for the treatment of acute cystitis.