Current practices for diabetes management rely on monitoring blood glucose levels. The aim of this study was to estimate the glucose levels of saliva, to assess if there is any significant correlation exists between the serum and salivary glucose levels in children with diabetes mellitus type 1. This study was a Prospective case control study included 80 Children aged between 4 and 17 years devidied into case group (60 cases) with Confirmed diagnosis of DM type 1 according to the diagnostic criteria by the American Diabetes Association . Controls included 20 healthy controls with matched age and sex compared to cases.All patients were advised to be fasting till both blood and salivary samples were collected.Patients were subjected to the following laboratory investigations:Blood glucose and glycosylated hemoglobin and Salivary glucose. Salivary glucose showed a significant elevation in the saliva in cases compared to controls (3.67 vs. 0.8 mg/dlp < 0.001). There was a significant positive correlation between salivary glucose levels and both of serum glucose and HbA1C levels (p < 0.001). Using a cut off value of 0.93 mg/dl, salivary glucose had sensitivity and specificity of 100 and 85% respectively in identifying cases with type I diabetes, with an accuracy of 96.25%. salivary glucose is a reliable indicator for both blood glucose and glycosylated hemoglobin levels in patients with type I diabetes mellitus