BACKGROUND: The principals of therapeutic recreation underpin a camping program for children and adolescents living with chronic disease. This study aimed to evaluate the campers’ health-related quality of life (HRQoL) before and after the program. METHOD: We used the Hungarian version of Kidscreen-52 questionnaire to assess HRQoL. The study sample (n = 115) consisted of children and adolescents aged 10-18 (Mean Age: 13,34; SD: 2,20) collected two months before and two months after camp with the following illnesses: oncology patients (n = 32), diabetes (n = 55) and juvenile immune arthritis (JIA) (n = 28). Repeated measures of multivariate analysis of variance (MANOVA) evaluated pre and post camp changes. We used the Reliable Change Index (RCI) to calculate all the 10 subscales of clinically significant changes. RESULTS: The Self-perception subscale showed significant positive change from pre camp to post camp with small effect size. Autonomy scores showed time related decline as well as significant time and age group interaction: children under 14 years of age showed a significant moderate effect size decrease on the Autonomy subscale. 32 children (27.8%) showed clinically significant improvement (RCI > 1.96) at least on one subscale. All positive changes were independent of the type of disease, age, gender, and previous camp experience. CONCLUSION: The therapeutic recreation camping program had a positive impact on HRQoL of children and adolescents living with cancer, diabetes mellitus and JIA. The experience enhanced their self-perception in all age groups and reduced the autonomy of children under 14 years of age. This study is an innovative use of the KIDSCREEN-52 questionnaire to measure the outcome effectiveness of a psychosocial rehabilitation program and to assess and compare HRQoL of children living with different chronic diseases.