The levels of specific IgG antibody to pneumococcal capsular polysaccharides were investigated in 182 children, aged 2-5 years, who were hospitalized for community-acquired pneumonia, including 55 (30.2%) with evidence of acute pneumococcal infection. Results show that children with concentrations of specific IgG antibody that would protect against invasive disease do not seem to be protected against pneumonia associated with pneumococcal infection.