Objectives: It is generally accepted that maternal factors are important in maintaining the adequate nutritional status of young children. This study was aimed at verifying whether mother’s socio-demographic (age and relationship status) and socio-economic features (education and professional status) differentiate the child’s nutritional status. Material and Methods: A cross-sectional study was conducted between April and October 2013. Five hundred thirty mothers of preschool children from 5 different regions of Poland were interviewed. Mothers were interviewed on their socio-demographic and socio-economic status. To assess the child’s nutritional status, body mass index (BMI) z-score and the diet indicators were calculated, such as the percentage of the estimated average requirement for energy (%EAR), the percentage of energy coming from carbohydrates (%EC), fat (%ET) and proteins (%EP). Percentage of the estimated average requirement for energy, %EC, %ET and %EP was obtained from 24-h dietary recalls conducted with the mothers. Results: The results showed that mother’s education and professional status did not differentiate any of the indices of the child’s nutritional status. However, maternal age and her relationship status occurred significant (ANOVA; p < 0.05). Children of younger mothers had higher BMI z-score and higher %EC as compared to children of older mothers. Moreover, %EAR was higher among children of single mothers and it was closer to the recommended nutrition standards as compared to children of mothers with a partner. Conclusions: When a child is diagnosed with any type of malnutrition, it is worth assessing various factors that might influence the nutritional status, such as child’s social background (e.g., maternal factors). Int J Occup Med Environ Health 2017;30(5):811–821