This study examined the relationship between locus of control and self-efficacy in a group of children and adolescents with respect to their adherence to treatment against type 1 diabetes and their general quality of life. The study is of correlational nature and uses a convenience sample of 40 children and adolescents with type 1 diabetes who were recruited at the Pediatric Diabetes Consultation of the Alto Ave Hospital Center. The instruments used were: The Socio-demographic and Clinical Questionnaire; Children Health Locus of Control; Self-efficacy Diabetes Scale; Diabetes Self-care Questionnaire and The Quality of Life and Diabetes Questionnaire. We used biochemical analysis of glycosylated hemoglobin. The main results indicate the influence of the locus of control in self-care and in some quality-of-life components. The self-efficacy does not have a statistically significant influence on therapeutic adherence but is connected to some components of quality of life. The results also show a significant correlation between therapeutic adherence and several components of quality of life.