Type 1 diabetes (DMT1) is the most common endocrinological disease in children and adolescents. It is characterized by an absolute lack of insulin due to the destruction of the pancreatic B cells resulting in hyperglycemia. The disease requires timely and adequate treatment to optimize the level of blood glucose. Otherwise, it results in various acute and chronic complications which can impair the quality of life of the affected child in the short and on the long term. On the other hand, the negative impact of the disease on all aspects of life can be significantly reduced by an integrated approach to treatment by using proper insulin doses, diet and regular physical activity according to the education. The aim of this research was to assess diet and lifestyle habits and the impact of the disease on the quality of life of children with DMT1 hospitalized in General hospital Vinkovci. By using the study-specific questionnaire, 25 parents of children diagnosed with DMT1 participated in this observational study. The average age of the children is 13.52±5.1 years (from 4 to 27 years; 48% male, 52% female). The average value of HbA1c is 7.136% and HbA1c<7% is achieved by 44% of children. 48% of parents consider themselves well educated about diabetic diet. Even though only 20% of parents estimate their child's energy needs correctly, 62,7% of them adhere to the intake of units of individual food groups. 88% of children engage in regular physical activity. The disease did not significantly impair the social life, psychophysical condition nor the quality of life of the children. The results of the research indicate the need for continuous education of parents, and later also of children suffering from DMT1.