Introduction : In Egypt, there is a paucity of biomarker data on aflatoxin (AF) exposure. Aim of the work : The aim of the work is to explore the degree of contamination of breast milk with aflatoxins in Egyptian mothers, the effect of aflatoxins on liver enzymes and prothrombin concentration of positive aflatoxin mothers and their infants and its effect on the weight of their infants. Subjects and methods : The study was conducted on One hundred and fifty mothers randomly chosen from pediatrics hospital of Cairo university inclusion criteria included exclusively breast feeding mothers without any supplements, mothers giving any sort of supplements were excluded. Results : 98 subjects (65.3%) were aflatoxin positive, and 52 subjects (34.7) were aflatoxin negative. Mean of age in positive cases was 23.9± 5.5 and in negative subjects 24.6±3.7. The subjects consider aflatoxin positive if level more than 0.05 mg/L, in this study the positive subjects levels were 7.1±5.0 mg/L and the negative subjects levels were 0.04±0.1 mg/L. The prothrombin concentration in aflatoxin negative subjects were higher than in positive aflatoxin subjects. ALT and AST was higher in aflatoxin positive mothers 35±20.8 and 35±19.5 than aflatoxin negative mothers 19.9±8.7 and 22.7±8. Prothrombin concentration was higher in negative aflatoxin mothers 90.2±7.8 than in positive aflatoxin mothers 87.3±9.9 ALT of infant of positive aflatoxin mothers 22.4±8.8 were significantly higher than ALT of infant of negative aflatoxin mothers 19.0±8.8 The weight of infant after 6 months of negative aflatoxin 6.1±0.6 was significantly higher than positive aflatoxin mothers 5.5±0.9 P-value ≤0.05 The correlation between aflatoxin and weight after 6 months of positive aflatoxin mothers was in negative direction P-value is less than 0.05.