Breast milk is a unique and highly beneficial source of nutrition for infants. It contains a wide range of nutrients that are specifically tailored to meet the specific needs of a growing infant. On the other hand, obesity is a major health issue that affects people around the world. The aim of this study is to investigate the relationship between breastfeeding and child BMI and the role of maternal BMI, which may influence this relationship. This study revealed that a longer duration of exclusive breastfeeding was associated with a decrease in the prevalence of overweight children. Additionally, the research found that children born to overweight or obese women had a higher probability of being overweight or obese themselves. Considering that mothers with a higher pre-pregnancy body weight are more likely to have children with a higher BMI, it is important that they receive information about the advantages of breastfeeding for a minimum of 6 months for both themselves and their children. Additionally, they should be offered ongoing support, to encourage them to start breastfeeding and continue with it beyond this period.