This study evaluates dental caries status and their related factors in a group of children at Mahidol University Pediatric Dental Clinic, Bangkok, Thailand. One hundred and four Thai children at Mahidol University Dental Clinic with the age six years and under (mean age=47.62±12.29 months) were sampled. Caries and plaque examination of children and their mothers were conducted. all parents completed the questionnaires regarding demographic data of children and parents, feeding and dietary habits, oral hygiene care, and child dental visit. Twenty-nine percent of children were caries-free and the mean dmft of children was 7.00±6.15. Almost twenty six percent of children had dmft ranging from 6 to 10. Five statistically significantly protective factors for dental caries were found in the analysis. These were: fluoride supplementation, having water fed after bottle feeding, cleaning oral cavities for babies under one year of age, mother level of education beyond high school and having milk as a snack. Children having sweets and desserts regularly, having the bottle held in the mouth while sleeping, and plaque accumulation, were three factors that found to be positively associated with dental caries. When using multivariate model for prediction of dental caries among studied children, having the bottle held in the mouth while sleeping was the only significantly predictor in the studied model. The results suggest that children who have the bottle held in the mouth while sleeping is the only significant risk group in the studied children.This study evaluates dental caries status and their related factors in a group of children at Mahidol University Pediatric Dental Clinic, Bangkok, Thailand. One hundred and four Thai children at Mahidol University Dental Clinic with the age six years and under (mean age=47.62±12.29 months) were sampled. Caries and plaque examination of children and their mothers were conducted. all parents completed the questionnaires regarding demographic data of children and parents, feeding and dietary habits, oral hygiene care, and child dental visit. Twenty-nine percent of children were caries-free and the mean dmft of children was 7.00±6.15. Almost twenty six percent of children had dmft ranging from 6 to 10. Five statistically significantly protective factors for dental caries were found in the analysis. These were: fluoride supplementation, having water fed after bottle feeding, cleaning oral cavities for babies under one year of age, mother level of education beyond high school and having milk as a snack. Children having sweets and desserts regularly, having the bottle held in the mouth while sleeping, and plaque accumulation, were three factors that found to be positively associated with dental caries. When using multivariate model for prediction of dental caries among studied children, having the bottle held in the mouth while sleeping was the only significantly predictor in the studied model. The results suggest that children who have the bottle held in the mouth while sleeping is the only significant risk group in the studied children.