Background: Early dental caries in childhood is one of the health problems. This survey was carried out to determine the prevalence of dental caries and its contributing factors among 3-6 year old children in Varamin, Iran kindergartens. Methods: In this cross-sectional study, 838 children aged 3-6 years from Varamin kindergartens were selected by census and examined for dental caries using WHO criteria. Variables including age, gender and the location of kindergarten were recorded in a check list. The socioeconomic state of kindergartens’ locations, were classified as high, moderate and low level by the consensus of 5 informative natives and governmental experts. Data were analyzed using Kappa, Mann-Whitney U, Chi-Square, Kruskull Wallis, and Spearman's Correlation Coefficient. Results: The mean score of dmft index (Decayed/ Missed/ Filled Tooth) in the studied children was 3.99±4.30 and 28.2% of children were caries free. dmft score showed a significant direct relationship with age. Children in rural areas had significant higher mean dmft score compared to children in urban areas (P=0.056). There was no significant statistical difference between dmft and gender or socioeconomic status of the location of kindergartens. Conclusion: The results indicate a high prevalence of early dental caries in Varamin children. Therefore, particular emphasis should be placed on educational and interventional programs, especially for mothers and kindergarten nurses and trainers.