In a multicenter, randomized, open comparison of meropenem to ceftazidime as empiric treatment of severe acute infections, 185 children (1 mo-15 years old, mean 65.4 mo) were enrolled. Meropenem (20 mg/kg t.i.d. i.v.) was given to 98 and ceftazidime (10-30 mg/kg t.i.d. i.v.) to 87 children, generally for 5 to 10 days (mean: 6.9 for meropenem and 7.5 for ceftazidime). Clinical response was evaluated at the beginning and at the end of therapy and 4 weeks later (follow-up). Clinical response was deemed satisfactory at the end of therapy in 96.7% of the patients treated with meropenem and in 95.3% of those who received ceftazidime without any statistically significant difference. One relapse occurred in a meropenem-treated patient at the follow-up clinical assessment. The baseline infecting organism was eradicated or presumed eradicated at the end of therapy in 14/16 patients treated with meropenem and in 14/15 treated with ceftazidime. The incidence of drug-related adverse events (mostly a slight increase in liver enzymes) was 9.2% in the meropenem group and 4.6% in the ceftazidime group. Our data show that meropenem is as effective as ceftazidime in the empiric treatment of severe infections in infants and children.