Pharmacokinetic and clinical evaluations of cefpirome (CPR), a newly developed cephalosporin, were performed in the field of pediatrics. The results are summarized as follows. 1. Peak serum concentrations of CPR after a dose of 20 mg/kg via 30 minutes and that via 60 minutes intravenous drip infusion and a dose of 40 mg/kg via 60 minutes intravenous drip infusion were 80.8, 63.7 and 128.8 micrograms/ml, respectively, with half-lives being 1.41, 1.28 and 1.79 hours, respectively. Urinary excretion rates for CPR in the first 6 hours after administration ranged 66.7-77.1%. 2. The clinical efficacy rate in pediatric infections obtained at daily dose levels ranging 55.6-166.7 mg/kg was 95.7%. 3. The eradication rate for 22 strains identified in the study was 95.5%. 4. Side effects were found in 2 cases of diarrhea. The abnormal laboratory test results were observed in 5 cases with 7 test items (increased number of platelets; 2 cases, increased activity of GOT; 2 cases and increased activity of GPT; 1 case). According to these results, CPR was considered to be a useful antimicrobial agent in pediatric infections.