Cefodizime (CDZM, THR-221), a newly developed injectable cephem antibiotic agent, was evaluated for its distribution in intrapelvic genital organ tissues, penetration into exudate of retroperitoneal space and breast milk and therapeutical effects on some infections in obstetrics and gynecology. The results obtained are summarized as follows. 1. When 1 g of CDZM was administered by drip infusion over a 60 minutes period, its serum concentration reached 53.51 micrograms/ml at the completion of drip infusion, then declined rapidly. Peak concentrations of CDZM in intrapelvic genital organ tissues were higher than 20 micrograms/g at different times. CDZM was transferred to the exudate of retroperitoneal space and its concentration reached a peak of 7.01 micrograms/ml at 2.67 hours after initiation of 60 minutes drip infusion at a dose of 1 g, then declined slowly but stood at 4.93 micrograms/ml even at 8 hours. The transfer of CDZM to breast milk was similar to other cephem antibiotic agents and peak levels of CDZM in milk were 0.13-0.36 microgram/ml at 2 or 3 hours after administration of a dose of 1 g. 2. In the clinical study, CDZM was administered by drip infusion over 60 minutes to 6 patients with obstetrical and gynecological infections at a daily dose of 2-6 g. Clinical results were good in 5, poor in 1, and the efficacy rate was 83.3%. No side effects nor abnormal laboratory test results were observed.