We studied the clinical efficacy of meropenem (SM-7338, MEPM), a new parenteral carbapenem beta-lactam antibiotic, in pediatric field. Thirteen patients with 2 months to 8 years and 8 months of ages, with acute infectious diseases were administered with doses at 39.3 to 76.7 mg/kg/day of MEPM intravenously. The diagnoses consisted of 7 respiratory tract infections, 1 sepsis, 2 orbital cellulitis, 1 parotid abscess, 1 lymphadenitis and 1 pyoderma. The clinical efficacy rate was 84.6% (11/13), and the bacteriological eradication rate was 71.4% (5/7). Clinical laboratory examinations revealed 1 patient with eosinophilia and another with anemia. No other side effects attributable to this drug were observed. It appears that MEPM is a useful antibiotic for moderate to severe acute bacterial infections in children.