Cefpirome (CPR), a new synthetic cephalosporin antibiotic, was administered to 10 patients with infectious diseases. The patients included 5 boys and 5 girls from 1 month to 5 years of age. They were given the drug intravenously at dosages ranging 53-100 mg/kg/day for 4 to 10 days. Clinical efficacy was evaluated in 9 patients: excellent in 2 patients, good in 6 patients and fair in 1 patient. The overall efficacy rate was 88.9%. No adverse effects were observed except in one patient who showed a slight increase of serum GOT and GPT.