Objective: Type 1 diabetes is a chronic illness which can have a negative effect on the health care and development of children and can put their lives in danger. This descriptive study aimed to determine the quality of life and the factors affecting it of children and adolescents with type 1 diabetes using the Pediatric Quality of Life Inventory (PedsQL).Methods: The study was conducted in the Child Endocrinology Unit of a University Hospital in Bursa, Turkey. Totally 64 children eight-12 years and 85 adolescents aged 13-18 with type 1 diabetes and their parents were recruited. HbA1c measurements were obtained from the records of the endocrinology clinicare, which were made once every three months, and the average of the last three measurements was taken in the study. The PedsQL was used to measure quality of life of the children and adolescents. The data was analyzed using SPSS version 20.0 and P<0.05 was considered significant. The demographic data of the children and parents were analyzed using means and percentiles. Pearson’s correlation analysis was used to assess the relationship between two averages. Results: Of the sub-groups on the scale, affective and school function scores were somewhat low, and social function scores were high. The quality of life scores of the children and adolescents were found to correlate with those of their parents. A negative correlation was found between HbA1c levels and adolescent quality of life, a positive correlation was found between the child’s age and the quality of life of the child and parents, and a negative correlation was found between the number of children in the family and the quality of life of the child and parents. Conclusions: An evaluation of the quality of life after a diagnosis of diabetes can be used to assess the problems which may be faced by children and adolescents and to combat these problems.