Childhood diet has a significant influence on diet-related diseases in adulthood, so an understanding of environmental influences on nutrition, is important. The aim of this cross-sectional study was to indicate family factors associated with some aspects of children’s nutrition in Central Poland. A questionnaire was used to investigate 892 mothers’ approach to breastfeeding, frequency of eating with children at fast food restaurants, and serving them snacks, sugary drinks, and fried food. Prevalence of dental caries among children, based on the mothers’ self-assessment, was also assessed. Majority of the mothers breastfed for a period not longer than six months. There was a positive association between breastfeeding duration and mothers’ education level and the number of children in a family. Sweets were used as a reward, more often among younger children and in families with higher number of children. The frequency of consumption of sweet beverages rose with the child’s age and decreased with mother’s education level and family income. It was also more frequent in rural areas. Most children received snacks and fried food at least once a week. There was a negative association between eating with parents at fast food restaurants and, both, the number of children in the family and living in a village. Fast food consumption rose with the mother’s education level and family income. Prevalence of dental caries according to mothers’ declarations was much lower than in national studies but was associated with frequent consumption of snacks and sweet beverages in the examined population. Extensive activities to reduce the occurrence of dental caries at the national level and education concerning the role of a family environment in providing a proper childhood nutrition, with a special emphasis on breastfeeding benefits, seems necessary for Polish parents. Designing community-wide education campaigns referencing population-based programs and other health and disease prevention activities, need to be promoted.