Cefpimizole (AC-1370) concentrations in the pelvic dead space exudate were determined in patients under-going curative resection of carcinoma of the uterine cervix to study the transfer of the drug into the female genital organs, and the results were statistically analyzed, using the two-compartment model. When 1 g of AC-1370 was administered by intravenous drip infusion over 1 hour, the AC-1370 concentration in the serum from the antecubital vein reached a level of 129.09 micrograms/ml at 1 hour of intravenous drip infusion, and the AC-1370 concentration in the pelvic dead space exudate reached a peak of 30.32 micrograms/ml at 2.51 hours of intravenous drip infusion, and remained at not less than 12 micrograms/ml 8 hours after the beginning of the drip infusion, with the area under the curve (AUC) for the AC-1370 concentration in the pelvic dead space exudate being 213.66 micrograms X hr/ml. Seven patients with obstetrical and gynecological infections were treated with 1 g of AC-1370 by intravenous drip infusion over 1 hour, 2 approximately 3 times daily. Although the patients all had rather mild infections, the treatment was effective in all of them. The findings in this study proved a dose of 1 g of AC-1370 at a time to be sufficiently effective in mild cases, but in view of the transfer of the drug into tissues, it seemed necessary to administer 2 g of the drug at a time in severe cases.