Background: Prolonged bottle and breast feeding may result in Early Childhood Caries (ECC). The clinical appearance of teeth in ECC in the children is typical and follow a definitive pattern. The goal of this study was to investigate the prevalence of ECC and its dependent factors in Hamadan Kindergarten’s children in 2006.

Materials and Methods: In this cross-sectional descriptive study, ECC data were collected using questionnaires from 414 children with age range of 2-6 years by a dentist. The relationship between early childhood caries and bottle or breast feeding, period of feeding, use of sweetening materials, frequency of feeding at night, and first time brushing were recorded. Data were analyzed with T-test and Chi- square test.

Results : The prevalence of ECC was 31.7%. The most affected teeth were left maxillary incisors (28.01%) and least affected left lower canine (0%). There was a meaningful correlation between breast feeding and ECC. There was no correlation between ECC and age, sex, first time brushing, feeding period, use of sweetening materials, bottle feeding and feeding at night.

Conclusion: The prevalence of ECC was high in the studied population and there was a relationship between breast feeding and it's duration with ECC.