BACKGROUND Childhood and adolescent cancer survivors (CACS) face a high risk for experiencing physical and psychological problems after the completion of their treatment. Effective healthy lifestyle interventions and strategies to improve their health-related quality of life are needed to prevent these problems. TherefThe object of this study was to investigate the effect of healthy lifestyle intervention study to improve the health-related quality of life in children and adolescent cancer survivors.ore, it should be preceded by verifying the effectiveness of various existing studies on the healthy lifestyle interventions of CACS. OBJECTIVE The object of this study was to investigate the effect of healthy lifestyle intervention study to improve the health-related quality of life in children and adolescent cancer survivors. METHODS MEDLINE via PubMed, Embase, PsycINFO, Cochrane Library, Web of Science, CINAHL, and several Korean web-based databases were searched for English written original articles published between January 1, 2000, and May 2, 2021. Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) were included. Each individual study was assessed independently by two authors for quality assessment using the revised Cochrane risk-of-bias tool (RoB 2) for randomized trials and the ROBINS-I for non-randomized studies. Meta-analysis was conducted using RevMan 5.3 software. RESULTS A total of 19 studies were included in this study. Quality of life was significant when interventions were given as a mixed approach (exercise and education) (d = -0.46, 95% CI [-0.84,-0.07], P = 0.02), not less than six months (d = -0.72, 95% CI [-1.15,-0.29], P = 0.0010), group approach (d = -0.46, 95% CI [-0.85,-0.06], P = 0.02). Self-efficacy, one of the psychosocial outcomes, showed significant effect when interventions were provided with health education only (d = -0.55, 95% CI [-0.92,-0.18], P = 0.003), less than six months (d = -0.40, 95% CI [-0.69,-0.11], P = 0.006) and individually (d = -0.55, 95% CI [-0.92,-0.18], P = 0.003). The physical outcomes (physical activity, fatigue, exercise capacity-VO2, exercise capacity-upper body, BMI) revealed no statistical significance CONCLUSIONS The area of healthy lifestyle interventions (HLSIs) of CACS that have not yet been actively studied were identified, and the need and direction of research for holistic health management could be suggested. CLINICALTRIAL NA