<p><strong>Abstract</strong></p><p><strong>Objective:</strong> To determine the clinical characteristics of newly diagnosed type 1 diabetes mellitus (T1DM) in children under15 years of age. Cross sectional study conducted at Aseer Central Hospital Abha, South-western Saudi Arabia from June 2011 – May 2015.</p><p><strong>Patients and Methods:</strong><strong> </strong>Study included 141 Saudi children, < 15 years old with newly diagnosed T1DM. The demographic and laboratory data were collected from file records. The patients were divided into younger (< 5 yr), middle (5 – 10 yr) and older (>10 – 15 yr) age groups. Data were analyzed by using SPSS version 16.</p><p><strong>Results:</strong><strong> </strong>Age of 141 children at onset of T1DM (mean ± SD) was 6.5 ± 3.2 years and majority 62 (44%) belonged to middle age group. Older 43 (30.5%) age group had female predominance (2:1) (p < 0.0001). Diabetic ketoacidosis (DKA) (39%), obesity (11%) and male predominance (2.6:1) were found in younger 36 (25.5%) age group (p < 0.0001). Family history (F/Hx) of T1DM 29 (20.6%) and HbA1c (10.36 ± 1.8%) successively increased with advancing age of patients. Main presenting symptoms like polyuria (96%), polydipsia (85%), weight loss (62%), nocturia (47%), polyphagia (28%) and DKA (22%),were significantly more frequent in children with F/Hx of T1DM (p < 0.0001). Duration of symptoms at first presentation was 17.3 ± 10.7 days and daily insulin requirement was found 0.82 ± 0.2 units/ Kg.</p><p><strong>Conclusion:</strong><strong> </strong>Polyuria, polydipsia, weight loss, noctu-ria and polyphagia were the main presenting symptoms and more frequent in middle age group children especially having F/Hx of T1DM. Under five years, obese and male children were found at higher risk for DKA development. Girls usually present late in adolescent age.</p>