Objective To understand the experience of children and adolescents living with type 1 diabetes and celiac disease. Method This is a qualitative exploratory-descriptive study. The participants were 3 children and 2 adolescents. The data were collected by means of semi-structured interviews between January and September 2012 at the participant's residence or at the diabetic outpatient clinic of the Hospital das Clinicas, Faculty of Medicine, University of Sao Paulo in São Paulo, Brazil. The content analysis technique was used to process the data. Results The key aspect of the illness experience of the patients was their diet, but with different meanings. The children had difficulty following the diet, while the adolescents reported that they had greater difficulty coping with the social and affective aspects of their diet. Conclusion The results reinforce the importance of nurses who seek strategies, together with the patients and their families, that help minimize the difficulties of these patients, especially with regard to managing the diet imposed by both diseases.