To investigate the safety, efficacy and recurrence-inhibiting effect of a single dose of levofloxacin (LVFX) for the treatment of acute uncomplicated cystitis in women, 56 females with acute uncomplicated cystitis between 17 and 73 years old were studied, based on the urinary tract infection (UTI) drug efficacy evaluation. The patients were divided into two groups; in Group A a single 200 mg dose of LVFX was administered, while in Group B, 100 mg of LVFX was administered twice a day for three days. The patients were re-examined three days later. The presence or absence of recurrence was surveyed by a questionnaire 3 months after the treatment. The efficacy rate on the third day after the administration in Group A and Group B was 96.9% (32 cases) and 95.8% (24 cases), respectively, and the recurrence rate within three months after administration 17.4% (4 in 23 cases) and 5.6% (1 in 18 cases), respectively. As for adverse drug reaction, abdominal pain was seen in one case, without a clear cause-effect relationship. Although the number of cases studied was small, no significant difference was seen between the single dose group and 3-day dose group in the safety, efficacy and recurrence-inhibiting effect of the new quinolone antibacterial treatment for acute uncomplicated cystitis in women, confirming the usefulness of the single dose treatment.