To expand upon the limited comprehensive population-based data for childhood bacterial meningitis in Eastern Europe, the present study was conducted in the Iasi and Constanta districts of Romania. From March 2000 through March 2002, children <5 years of age hospitalized for bacterial meningitis were enrolled in a prospective surveillance study. A total of 56 cases of bacterial meningitis were identified, including 37 due to Neisseria meningitidis (22 per 100,000 per year), 13 due to Haemophilus influenzae type b (7.6 per 100,000 per year), and six due to Streptococcus pneumoniae (3.5 per 100,000 per year). Of the 31 meningococcal isolates that were serotyped, 12 were serogroup A, eight were serogroup B, and 11 were serogroup C. Among all cases of bacterial meningitis, 25 occurred in children <1 year of age, including those due to meningococci (n=14), H. influenzae type b (n=7), pneumococci (n=3), and Klebsiella pneumoniae (n=1). In Romania the incidence of H. influenzae type b meningitis is similar to that found in other areas of Southern and Eastern Europe during the pre-vaccination era, and the incidence of meningococcal meningitis is one of the highest yet found in Europe. An unexpectedly high proportion of these meningococcal meningitis cases is due to serogroup A. Disease burden could be substantially reduced through the introduction of H. influenzae type b conjugate vaccine and, when available, meningococcal conjugate vaccine protective against serogroups A, B and C.