The Clinical Practice Guidelines on the Management of Type 1 Diabetes Mellitus in Children & Adolescents was developed by a multidisciplinary development group and approved by the Ministry of Health Malaysia in 2015. A systematic review of 15 clinical questions was conducted using the evidence retrieved mainly from MEDLINE and Cochrane databases. Critical appraisal was done using the Critical Appraisal Skills. Recommendations were formulated on the accepted 136 evidences using the principles of Grading Recommendations, Assessment, Development and Evaluation tailored to the local setting. Type 1 diabetes mellitus is a chronic disease, which usually occurs at an early age, and is associated with various complications including retinopathy, nephropathy, neuropathy and cardiovascular morbidity. Good glycaemic control early in the disease results in lower frequency of chronic diabetes complications, which in turn reduces the healthcare cost. Accurate classification of diabetes and optimum management with the aim to achieve glycaemic targets is of utmost importance.