Abstract Background Infant growth is a big concern among the community, mothers and the pediatricians, this study focused on what can affect newborns growth in Egyptian community. Objective Primary objective to detect the relationships between protein and lipid content of the breast milk of Egyptian women with their infant’s growth. Secondary objective is to correlate protein and lipid content in the mother’s milk and their diet. Patients and Methods This is a cohort study done on 30 infant in Ain Shams University for a period of six months.history was taken by questionnaire about infant’s Gestational age. parity. Dietetic history of infant (breast fed, frequency of feeds),Mother’s age, education, address, body weight, height, BMI and maternal illness. Mother’s dietetic history by 24 hour recall.breast milk samples was collected by hand expression between 4 and 8 weeks of lactation, kept frozen at20 °C. Triglyceride (fat) concentrations were measured in homogenized HM samples using H-Nuclear magnetic resonance (NMR) spectra. For protein, total nitrogen was measured by the Dumas method. Results The growth rate range of infants under study was (18gm/day _ 28gm/day). Protein content of mother’s milk lowest value was 0.7gm, and highest value was 1.9gm. Lipid content of mother’s milk lowest value was 3.1gm, and highest value was 5.6gm. Lactose content of mother’s milk lowest value was 5.9gm, and highest value was 7.4gm.Caloric content of maternal diet lowest value was 1013kcal/day and highest value was 2818kcal/day. the protein of breast milk has a direct positive effect on Infant’s growthrate(r = 0.735,p=0.000)weight(r = 0.689,p=0.000)and z score(r = 0.573, p = 0.001).lipid content of breast milk has a positive effect on Infant’s growthrate(r = 0.677,p=0.000)weight(r = 0.742,p=0.000)and zscore(r = 0.592,p=0.001). Protein of maternal diet has an impact on the protein content of her breast milk(r = 0.719,p=0.000)and lipid content of breast milk(r = 0.712, p = 0.000).lipid of maternal diet has no effect on lipid content of breast milk(r = 0.127,p=0.52)and protein of breast milk (r = 0.118,p=0.536).caloric intake of mothers has positive effect on protein of breast milk(r = 0.599,p=0.000),and lipid of breast milk(r = 0.496,p=0.005). Conclusion Protein content of breast milk of mothers positively affects growth rate weight and height of their infants. (P value 0.000, 0.001,0.005 respectively). As protein content of breast milk exceeds 1.1gm/dl infant kept same or higher weight/height centile and z score. As lipid content of breast milk exceeds 4mg/dl infant kept same or higher weight/height centile and z score. Protein content of breast milk is positively affected by protein in maternal diet(r = 0.747,P 0.000) and her total caloric intake(r = 0.519,p 0.005).lipid content of breast milk is positively affected by protein content of maternal diet (r = 0.719,P 0.000)and her total caloric intake(r = 0.496,p 0.005).