Hypothesis: Environmental factors affect the risk of development of type 1DM. Diabetes-associated autoantibodies may be useful in the assessment of diabetes risk among the first-degree relatives (siblings) of diabetic cases. Objectives: To identify the relative contributions of environmental risk factors of type 1 DM in children. To detect the emergence of insulin autoantibodies (IAA) Subjects and Methods: A case control study was carried out in the Diabetes, Endocrine & Metabolism Pediatric Unit, the Pediatric University Hospital – Faculty of Medicine, Cairo University. The total number of assigned children was (273) children. They were classified into 3 groups (n = 91/each); diabetic cases, first control group (siblings) and second control group (healthy). All subjects completed an interviewing questionnaire. Focus on many implicated environmental factors throughout the child’s life. The social standard and the anthropometric measurements were assessed. Type 1 DM risk assessment was estimated by using a designed risk assessment model and a risk assessment score. Subsamples from each group (n = 50) were assigned randomly and subjected to the predictive screening tests. Results: Type 1 DM could be significantly attributed to seasonality of birth, residence, pesticides, violence, maternal age, antenatal care, preeclampsia, emotional stress, C.S and early weaning (at ≤ 3rd month). Breast feeding was a protective factor. There were highly significant differences as regards the estimated total socio-economic, prenatal/natal risk scores. Significant differences were revealed as regards the emergence of IAA. The emergence of IAA was significantly related to many risk factors. Logistic regression analysis proved that maternal psychological risk and neonatal risk were positively predicting the emergence of IAA in the all investigated children. Conclusion: Type 1 DM and the emergence of IAA were significantly related to early environmental determinants.