There are few studies from developing countries on the epidemiology of Haemophilus influenzae (Hib) infections among infants and children. We set out to determine the prevalence of oropharyngeal Hib colonization among Turkish children younger than two years of age and to identify antimicrobial resistance among the isolates. A cross-sectional study was conducted on 818 healthy children and oropharyngeal secretions were sampled. The carriage rate of Hib was found to be 7·2% and this increased significantly with age. Carriage of Hib among 3- to 6-month-old children (3·5%) was higher than expected and was significantly higher among children who were passive smokers (P=0·04). Logistic regression analysis showed that breastfeeding status was the sole significant factor for colonization (OR 2·2, 95% CI 1·26–3·82). Antimicrobial susceptibility tests on 56 isolates of H. influenzae showed that 51·8% and 21·4% were resistant to trimethoprim–sulphamethoxazole and ampicillin respectively. Other notable resistances were to cefalexin (10·7%) and chloramphenicol (3·6%); no isolates were resistant to ceftriaxone.