This statement provides guidelines for therapy of children with serious infections possibly caused by Streptococcus pneumoniae. Resistance of invasive pneumococcal strains to penicillin, cefotaxime, and ceftriaxone has increased over the past few years. Reports of failures of cefotaxime or ceftriaxone in the treatment of children with meningitis caused by resistant S pneumoniae necessitates a revision of Academy recommendations. For nonmeningeal infections, modifications of the initial therapy need to be considered only for patients who are critically ill and those who have a severe underlying or potentially immunocompromising condition or patients from whom a highly resistant strain is isolated. Because vancomycin is the only antibiotic to which all S pneumoniae strains are susceptible, its use should be restricted to minimize the emergence of vancomycin-resistant organisms. Patients with probable aseptic (viral) meningitis should not be treated with vancomycin. These recommendations are subject to change as new information becomes available.