Data on resistance in Streptococcus pneumoniae was analyzed in cohorts of isolates from nasal carriers without respiratory tract infection, nose-throat swabs, and ear fluid specimens of children, from sputum and bronchoalveolar lavage of adults and central spinal fluid, blood, and pleural fluid of patients without a distinction of age group. Colonizing strains in infant carriers showed a higher resistance rate (47.5%) to penicillin than in other children (24.2%). Isolates of inpatients, predominantly infants with respiratory tract infection, presented a higher prevalence of resistance than outpatients in all age groups. Adults showed the lowest resistance rates. Resistance was rarer among S. pneumoniae isolates from patients with systemic infection. The few cases caused by resistant S. pneumoniae should raise concern. Resistance among strains from ear fluid was more prevalent in all investigated population groups than among isolates from throat-nose swabs. The similarity of resistance rates to erythromycin and penicillin was associated with frequent combined resistance. While the prevalent serotype among the resistant strains was 19A, no predominant serotype was found among the susceptible strains.