An investigation was carried out to determine the therapeutic effect of levofloxacin (LVFX) once-a-day oral therapy at the dose of 200 mg/day for 7 days on uterine cervicitis, in comparison with LVFX twice-a-day oral therapy at the dose of 200 mg/day for 7 days. Of the 102 patients enrolled in the study, 90 were subjected to the analysis. The efficacy rate on uterine cervicitis of the once-a-day therapy and twice-a-day therapy groups according to the evaluation of the Drug Efficacy Evaluation Committee were 72.0% (36/50) and 82.5% (33/40), respectively. The efficacy rate on uterine chlamydial cervicitis of the once-a-day therapy and twice-a-day therapy groups according to the evaluation of the Drug Efficacy Evaluation Committee were 88.0% (22/25) and 85.7% (18/21), respectively. Safety was evaluated as "safe" in 88 of the 90 assessable patients (97.8%). Side effects were seen in two cases, which belong to the once-a-day therapy group; mild candidiasis and mild breast distension sense. As the antimicrobial treatment started, the levels of the inflammatory cytokines, interleukin-6 (IL-6) and interleukin-8 (IL-8) in the cervical mucus, decreased. It is suggested that IL-6 and IL-8 can be useful indicators of the antimicrobial treatment in the uterine cervicitis. These results suggested that the LVFX once-a-day therapy can be useful on uterine cervicitis.