Introduction. The high incidence of early childhood caries (ECC) highlights the need to analyze the causes. Aim. Evaluation of the impact of diet and socioeconomic conditions on the risk of ECC development in children. Material and methods. A group of 686 pediatric patients aged 1-6 from the University Dental Clinic in Krakow was examined for caries. The parents were asked to complete a questionnaire on the eating habits of children and on the sociodemographic factors. Results. Children aged 1-2 from rural areas and average education of parents constituted a significant factor affecting the intensity of ECC. Consumption of sugary foods at night increased the occurrence of caries by more than 3.5 times in 1–2-year-olds, and by 4 times in 5-year-olds. Frequent consumption of fruit juices and carbonated beverages had a significant impact on the occurrence of caries in 6-year-olds. Conclusions. Dietary pattern is a major cause of ECC. The relationship between ECC and the place of residence, low parental education and poor economic status indicates the target group for intensive educational activities for the prevention of dental caries