T-1982 (cefbuperazone), a new cephamycin antibiotic, was fundamentally and clinically studied. The following results were obtained. Serum and internal genital tissue levels of T-1982 were measured following intravenous injection or intravenous drip infusion of 1 g. High serum levels of more than 10 micrograms/ml and tissue levels of more than 5 micrograms/g were maintained for 3 hours after intravenous administration. Favourable transfer of T-1982 into the pelvic dead space exudate was observed. The exudate level attained its peak at 2 hours and was 14.6 micrograms/ml on average even at 8 hours after intravenous infusion. With its MIC values, T-1982 was considered to be bactericidal against many Gram-negative bacteria except Pseudomonas sp. A total of 4 cases comprising 2 with pyometra, 1 with pelveoperitonitis and 1 with endometritis complicated with pelveoperitonitis was treated with T-1982 at a dose of 1-2 g twice daily by intravenous drip infusion. The clinical response was excellent in 1 case and good in 2 cases. A case with pyometra due to S. faecalis did not respond to the therapy. Side effects and abnormal laboratory findings due to the drug were not noted.