Cefpiramide (CPM, SM-1652), a new cephem antibiotic, was fundamentally and clinically studied. The following results were obtained. Serum and internal genital tissue levels of CPM were measured following intravenous drip infusion of 1 g. High serum levels of 30 micrograms/ml and tissue levels of more than 4 micrograms/g were at least maintained for 8 hours. Favourable transfer of CPM into the pelvic dead space exudate was observed. The exudate level was 7.25 micrograms/ml on average even at 8 hours after intravenous drip infusion. A total of 6 cases comprising 4 with Bartholin's cyst, 1 with pelvic peritonitis and 1 with lymphocyst was treated with CPM at a dose of 0.5-2 g twice daily by intravenous injection or intravenous drip infusion. The clinical response was excellent in 1 case and good in 5 cases. Side effects and abnormal laboratory findings due to the drug were not noted.