The aim of the paper was to present the basic methodological approaches to studying the quality of life of patients with regard to interdisciplinary character of the concept, its interrelation with standard of living, specificity in children and teenagers. Studying the quality of life of children and teenagers has specific character. According to modern recommendations, it is the basis of complex estimation of state of health of the child. Two basic methodological approaches are used: the first consists in selection and analysis of factors, significant for health of teenagers from adult people point of view; the second provides research of factors, significant from the point of view of teenagers. Techniques unite two types of criteria: 1. the objective: physical activity, social functioning; 2. the subjective: factors of emotional status, self-estimation of state of health, satisfaction by factors related with health, – that is perception by teenagers how their requirements for health are satisfied and how much possibilities necessary for it are given.