A new carbapenem antibiotic, meropenem (MEPM), was evaluated for its safety and efficacy in 33 infants and children. MEPM was effective in all the 32 evaluable cases including 4 cases of bacterial meningitis and 5 cases of Pseudomonas aeruginosa infections. The mean half life of plasma concentrations of MEPM was 0.84 +/- 0.09 hours after 30 minutes intravenous drip infusion. Mild diarrhea (2 cases), transient elevation of transaminases (8 cases), and transient eosinophilia (2 cases) were associated with the MEPM therapy, but none of them was problematic. These data suggest that MEPM is safe in infants and children and could be one of the therapeutic agents for severe infections or infections in compromised hosts.