Aim: Diabetes mellitus is a major public health problem worldwide. Type 1 diabetes mellitus (T1DM) is the most common metabolic chronic disease in genetically susceptible children and adolescents, due to an autoimmune process characterized by a selective destruction of insulin producing β-cells. The aim is to assess the epidemiological features of new-onset T1DM in children and adolescent at the national level during the period 2010-2014 in Department of Pediatrics, Endocrine Unit, University Hospital Center 'Mother Teresa', Tirana, as the unique center for pediatric endocrinology and diabetology in Albania.Methods: The clinical and laboratory characteristics of 152 patients aged <15 years newly diagnosed with T1D from 1 January 2010 to 31 December 2014 were studied. T1D was diagnosed according to WHO 2006 criteria and DKA was diagnosed based on ISPAD 2014 criteria. Patients were classified into 3 sub-groups (I: 0-4 years, II: 5-9 years, and III; 10-14 years). Statistical analysis was performed using SPSS 26. Results: The incidence of new-onset of T1DM was 5.012/100.000/year. The mean age of children at diagnosis was 8.3 ± 3.6 years. The patients were mostly diagnosed at ages 5-9 years (40.1%), and 10-14 years (39.5%), followed by the 0-4 years age group (20.4%). Mean duration of symptoms was 23.35 ± 17.16 days; longer in the subgroup 5-9 years (P= 0. 0.013). Three quarters (75%) of children with T1DM live in urban areas. Viral infections or other circumstance triggers were in 41.9% of children aged 0-4 years compared to other subgroups (P=0.002). Most of the children were born in the spring−summer months (53.23%) compared to the autumn−winter months (46.77%). Approximately 1/4 of the children were born and diagnosed with type 1 diabetes in each of the seasons of the year and 52.63% of the patients studied were first born. Family history for DMT1 and DMT2 is observed in 15.8% and 17.8% of the children, respectively. Polyuria (99.3%), polydipsia (99.6%) and weight loss (98.1%) were the most common symptoms and 67.8% of patients presented with diabetic ketoacidosis (DKA). Misdiagnosis was in 21 (13.8%) patients. Mean glycosylated hemoglobin A1c (HbA1c) was 11.63%; 11.9 ± 2.0 in DKA positive children and 11.1 ± 2.4 in DKA negative children (p= 0.195).At diagnosis and during follow up of T1DM 25% (38/152) developed associated autoimmune diseases; 68.42% at diagnosis of T1DM and 65.79% (25/38) of patients were female. During follow up children with T1DM developed associated CD and SAT, 2.54, and 2.19 years, respectively.Conclusion: Diabetes mellitus is one of the major public health problems worldwide. Albania is a country with middle incidence of T1DM and the age at onset is decreasing. The symptoms lasted significantly longer and mean HbA1c levels were significantly higher in older children. The incidence of DKA in children with newly diagnosed T1DM is high.