The efficacy and safety of ofloxacin taken orally once a day for three days was compared with a combination of trimethoprim and sulfamethoxazole (TMP/SMX) taken orally twice a day for seven days in the treatment of uncomplicated urinary tract infection. The diagnosis was established by the presence of symptoms including dysuria, frequency, suprapubic pain, and urgency. Bacteriuria was confirmed by a urine culture of a minimum of 10(5) organisms per mL, of at least one species. A treatment course of ofloxacin, once-a-day for three days, was as safe and effective as a standard course of TMP/SMX, twice a day for seven days.