Introduction and Objectives: Over the past few years, a surge in the incidence of Type 1 Diabetes Mellitus (T1DM) has been observed worldwide, especially during the COVID-19 pandemic. The aim of our research is to shed light on the incidence of Type 1 Diabetes Mellitus in children and adolescents at General Hospital "Dr. Laza K. Lazarević" in Šabac, as well as the impact of the COVID-19 pandemic. Methodology: General Hospital "Dr. Laza K. Lazarević" in Šabac serves a population of 35,141 children aged 0-19 years from the Mačva District territory. Data were collected through a retrospective analysis of electronic medical records of children and adolescents diagnosed with T1DM at General Hospital "Dr. Laza K. Lazarević" in Šabac from January 2013 to December 2022. Results: Throughout this ten-year period, the average incidence of Type 1 Diabetes Mellitus in children under 19 was 14.80 per 100,000, with the highest incidence found in the group aged 10-14 years and the lowest incidence found in the group aged 15-19 years. During the years of the COVID-19 pandemic, a slightly higher incidence was recorded compared to the years before the pandemic, although the difference was not statistically significant. Conclusion: Based on the data from our study, it is clear that the COVID-19 pandemic has had some impact on the occurrence of Type 1 Diabetes Mellitus in children, as it is associated with a higher incidence of T1DM compared to the years preceding the COVID-19 pandemic.