The nasopharyngeal carriage of Streptococcus pneumoniae is thought to pose a risk for invasive pneumococcal diseases, and the evaluation of carriage strains is thus often used to inform antibiotic treatment and vaccination strategies for these diseases. In this study, the age-specific prevalences, resistance to antibiotics, and serotype distributions of 1,340 carriage strains were analyzed and compared to 71 pneumococcal strains isolated from the cerebrospinal fluid of children under 5 years old with meningitis. Overall, the nasal carriage rate was 47%. One-fourth (26%) of the infants under 1 month of age and one-half (48%) of the infants under 12 months of age were colonized with S. pneumoniae. Rural children were colonized earlier than those from urban areas. Approximately one-fourth and one-half of the cases of pneumococcal meningitis occurred in the first 3 and 6 months of life, respectively. The respective rates of resistance for carriage and meningitis strains to penicillin (7 and 3%), cotrimoxazole (77 and 69%), and erythromycin (2 and 1%) were similar, whereas chloramphenicol resistance was lower among carriage strains (3%) than among meningitis strains (15.5%). The predominant serogroups of carriage and invasive isolates were variable and widely divergent. Thus, hypothetical 7-, 9-, and 11-valent vaccines, based on the predominant carriage strains of the present study, would cover only 23, 26, and 30%, respectively, of the serotypes causing meningitis. Further, currently available 7-, 9-, and 11-valent vaccines would protect against only 26, 43, and 48%, respectively, of these meningitis cases. In conclusion, while the surveillance of carriage strains for resistance to antibiotics appears useful in the design of empirical treatment guidelines for invasive pneumococcal disease, data on the serotypes of carriage strains have limited value in vaccine formulation strategies, particularly for meningitis cases.Streptococcus pneumoniae is one of the leading causes of childhood pneumonia and meningitis. It accounts for 20 to 40% of the estimated annual global burden of 2.7 million childhood deaths from pneumonia in developing countries (11,22,25) and is the most common cause of pneumonia and the second leading cause of meningitis in children in Bangladesh (26, 31).Data on the serotype composition and antibiotic resistance of invasive pneumococcal strains from the developing world are scarce. Previously, it has been shown that the serotype distribution of invasive S. pneumoniae in Bangladesh differs from the distribution in many other parts of the world, and the proposed conjugate vaccines developed on the basis of data from other, primarily Western, countries cover at most 50% of the invasive strains (29). High levels of resistance to cotrimoxazole and low levels of resistance to penicillin have also been found (28, 30); for Bangladesh, these findings bring into question the present World Health Organization recommendation that cotrimoxazole be used as a first-line empirical therapy for the treatment of pneumon...