In patients with carcinoma of the uterine cervix, cefminox (CMNX, MT-141) was given intravenously after panhysterectomy and the pelvic dead space exudate and serum levels of the drug were determined at various periods. The pelvic dead space exudate level reached its peak of 67.21 +/- 39.81 micrograms/ml at 2 hours, which decreased gradually to 26.04 +/- 6.66 micrograms/ml at 6 hours. In the serum, the drug level attained the peak of 152.98 +/- 85.37 of 7.26 +/- 1.66 micrograms/ml was still detected. The pelvic dead space exudate level was much higher than its MIC or 3h-MBC at all periods studied. From these results it was considered that CMNX achieves levels high enough to be expected of clinical efficacy in the pelvic dead space exudate and serum.