Background: Exercise-based rehabilitation is already a part of cystic fibrosis (CF) treatment; however, patient adherence is low. Objectives: To assess the effectiveness of a home exercise programme using active video games (AVGs) as a training modality for children and adolescents with CF. Methods: Thirty-nine children with CF were randomised to a control group (CG, n = 20, age 11 ± 6 years; FEV1 86.2 ± 20.5% of predicted) or a training group (AVGG, n = 19, age 13 ± 3 years; FEV1 82.7 ± 21.7% of predicted). The home training protocol consisted of 30- to 60-min sessions, 5 days/week, for 6 weeks using a Nintendo Wii™ platform. Exercise capacity was measured by the 6-min walk test (6MWT) and modified shuttle walk test (MSWT); muscular strength was estimated using the horizontal jump test (HJT), medicine ball throw (MBT), and hand grip strength (right [RHG]; left [LHG]); and quality of life was rated using the Cystic Fibrosis Questionnaire-Revised (CFQ-R). All the children were measured at baseline, after rehabilitation, and at 12 months. Results: For the group × time interaction ANOVAs, the AVGG showed significant between-group differences in exercise capacity: 6MWT farthest walking distance, 38.4 m (p < 0.01); MSWT farthest walking distance, 78.4 m (p < 0.05); and muscular strength: HJT 9.8 cm, MBT 30.8 cm, RHG 7 kg, and LHG 6.5 kg (p < 0.01), before versus after intervention. The CFQ-R reported significantly higher scores on respiratory symptoms after the intervention and favoured the AVGG, and there was an improvement in other domains after 12 months. Adherence to the home exercise programme was 95% during the 6- week intervention period. Conclusion: A home-based programme using AVGs can effectively improve exercise capacity, muscular strength and quality of life in the short-term in children and adolescents with CF. The effects of training on muscle performance and quality of life were sustained over 12 months.