To provide ongoing information on regional trends of antibiotic resistance prevalence to pneumococci, a cross selectional survey was conducted on a large representative sample of children attending day-care centers. Children were analyzed in spring (n = 378) and autumn (n = 379) for nasopharyngeal carriage. Streptococcus pneumoniae was detected in 149 children (39.4%) in Spring and 204 (59.8%) in Autumn. Half of these isolated strains showed penicillin insensitivity or resistance. A high proportion of children (43.6% in spring and 47.5% in autumn) had been treated with antibiotics during the 3 months prior to sample collection; 21.6% of isolated strains were serotype 6B, 20.1% type 23F, 18.9% type 19A and 19F, 11.5% type 14. Reduced susceptibility was frequently noted in serotype 23F, 14 and 19F, representing 93%, 94% and 46% of identified serotypes, respectively. Acquisition of a strain of PRP was correlated with prescription of antibiotics during the previous three months (p < 0.05). This type of survey on children in day-care centers can contribute to the understanding of regional variations in antibiotic resistance and provide information for epidemiological surveillance.