Quality of life depends on general health, psychological status, and independence in performing activities of daily living, social relationships and environment. Health status is only a part of quality of life, describing the physical and emotional aspects. The study used a questionnaire assessing the quality of life of children with diabetes. Questionnaires were ranked and specially adapted to affected children of certain age. The questionnaire consists of general data, subjective evaluation of quality of life and health, and seven other categories used to estimate the quality of life (physical functioning, emotional functioning, social functioning, and functioning in the school, symptoms of diabetes, treatment and communication). All children were diagnosed with type 1 diabetes. In most patients the disease has been detected after 2 years of age (97 %). The average age of diagnosing diabetes was 9. The average score of the quality of living was 8/10, and the lowest was 6/10. The respondents assessed health with average score of 8/10, while the lowest score was 5/10. According to the parents’ assessment lack of energy occurred in 60 % of children, i.e. fatigue, 77 % of children felt angry with themselves for being ill, while 60 % were nervous or ill-tempered, 43 % of children were worried that they would experience the episode of hypoglycaemia, while 50 % were worried about hyperglycaemia, 47 % of children had difficulties in maintaining concentration at school / kindergarten, 53 % were absent from school for seeing the doctor. Hunger occurred in 77 % of children, dizziness in 50 %, and hypoglycaemia in 83 % and hyperglycaemia in 87 %. Pain when taking therapy (insulin) occurred in 60 % of children. Diabetes strongly affects children and their parents. The study established negative impact mostly on emotional functioning, functioning in school, and in communication, but it did not limit the children in physical and social activities. The sick children have to deal with complex and demanding daily regimen for treatment with negative effect on the quality of life.