Latamoxef (LMOX) at a dose of 2 g was intravenously administered to 12 cases with postoperative meningitis and the concentrations in serum and cerebrospinal fluid (CSF) were examined up to 2 hours and the results obtained were as follows; The average serum and CSF concentrations of LMOX were 125.0 micrograms/ml, 4.33 micrograms/ml at 0.5 hour, 80.7 micrograms/ml, 4.64 micrograms/ml at 1 hour and 45.8 micrograms/ml, 3.82 micrograms/ml at 2 hours, respectively. The clinical responses of LMOX against postoperative meningitis were revealed excellent in 4 cases and good in 8 cases. No side effects were observed. LMOX was thought to be effective agent in the treatment of the postoperative meningitis.