Clinical study to evaluate the usefulness of cefpimizole (AC-1370) was made in the 6 patients with female genital organ infections. Two grams or 4 g of AC-1370 was administered a day by intravenous drip infusion ranging from 5 to 18 days. Responses were excellent in 2 cases, good in 3 cases and poor in 1 case, parametritis after hysterectomy. The efficacy rate was 83%. Neither general side effect nor abnormal laboratory finding was observed. AC-1370 showed a satisfactory clinical efficacy in treatment of the infections in the field of gynecology, and it has been concluded that AC-1370 will be an useful antibiotic for these infections.