The present study was performed to evaluate the clinical effectiveness and safety of cefmenoxime (CMX), a new cephalosporin antibiotic for injection in the field of pediatrics. Thirty-one cases, including 2 cases with sepsis, 18 cases with respiratory tract infections and 7 cases with urinary tract infections, were given CMX at daily doses of 30 mg/kg to 125 mg/kg divided into 3 or 4 for 3 days to 13 days. Clinical responses were excellent in 16 cases, good in 9 cases and poor in 6 cases, the satisfactory response being 80.6%. No side effects and no abnormal laboratory findings relating to the drug were observed.