Objectives: This study aims to assess the interaction between Breastfeeding and ALL incidence and different ALL variables in children. Methods: Our case-control study was conducted in the major paediatric cancer centre in Syria. Information was obtained from the hospital’s records of patients who did not have a hereditary or chromosomal syndrome and aged 4 years and less. The cases had ALL and controls were hospital inpatients. Children were divided into 3 groups depending on their feeding habits before the age of 6 months. Results: Sixty (85.7%) cases and 59 (72%) controls were exclusively breastfed. Exclusive breastfeeding was found more frequently in the case group P=0.04 (OR, 2.339; CI, 1.025 -5.336). In case group, parents of a low educational level breastfed their children more frequently (P<0.05). Number of siblings was not associated with ALL or any of its variables. Furthermore, infancy feeding pattern correlation with gender, being born with no complications, consanguinity, CD10, FAB classification, ALL-subtype, risk, and family history were insignificant. Conclusion: There are certain practices among the Syrian people, especially among parents of a low educational level that has possibly exposed to carcinogenic substances which were possibly transferred through BF. However, BF had minor effects on the prognosis and subtype of ALL, and number of siblings had no effect on ALL.