Background: Food can affect the brain throughout the entire life cycle. Cognition refers to the mental processes involved in the acquisition of knowledge and the integration of these processes into responses such as the intelligence quotient (IQ). Objective: The purpose of this study was to compare intelligence quotient of children aged 6-10 years who were breastfed in their post-natal life versus those who were not exposed to breastfeeding. Patients and methods: A case control study was conducted on 56 children in Zagazig University Children Hospital, during the period from October 2018 to March 2019. They were divided into two groups. Group I: 28 healthy children who were exclusively breastfed. Group II: 28 healthy children who were artificially-fed. All cases were subjected to: A constructed questionnaire assessing breastfeeding practices during the first two years as well as the current health status over the past years and current and past behavioral disorders. Clinical examination was done. Dietary assessment was done to assess current feeding and food intake practices. Special test; Wechsler and Primary Scale of Intelligence was done for all participants to assess the cognitive functions. Results: This study showed that, higher IQ in the breastfed group as compared to the artificially-fed group. Conclusion: Cognitive function of the child is increased with the increased duration of exclusive breastfeeding up to six months of age. The education of the mother positively influenced the IQ among children who were exclusively breastfed for 6 months but not the other groups.