Background Respiratory dysfunctions are an important cause of morbidity and death in cerebral palsy (CP) populations. Respiratory exercises in addition to conventional rehabilitation have been suggested to improve respiratory status in CP patients. The objective of this systematic review and meta-analysis was to verify the effects of the addition of respiratory exercises to conventional rehabilitation on pulmonary function, functional capacity, respiratory muscle strength, gross motor function and quality of life in children and adolescents with CP. Methods We searched for randomized controlled clinical trials in PubMed/Medline, Lilacs, SciELO, EMBASE and Physiotheraphy Evidence (PEDro) from their inception until July 2022 without language restrictions. Studies that included respiratory exercises (breathing exercise program; feedback respiratory training; incentive spirometer exercise; inspiratory muscle training; and combination of respiratory exercises + incentive spirometer exercise) in combination with conventional rehabilitation for children and adolescents with CP were evaluated by two independent reviewers. The mean difference (MD) and 95% confidence interval (CI) were estimated by random effect models. Results Ten studies met the eligibility criteria, including 324 children aged from 6 to 16 years. The meta-analysis showed an improvement in inspiratory muscle strength of 22.96 cmH 2 O (18.63-27.27, n = 55) and pulmonary function of 0.60 (0.38-0.82, n = 98) for forced vital capacity (L); 0.22 (0.06-0.39, n = 98) for forced expiratory volume at 1 second (L); and 0.50 (0.05-0.04, n = 98) for peak expiratory flow (L/min). Functional skills in daily living activities improved in the intervention group. Caregivers' assistance of daily living activities, functional capacity, gross motor function and expiratory muscle strength showed a nonsignificant improvement. Social well-being and acceptance and functioning domains improved in only one study. Conclusions Emerging data show significant enhancements in inspiratory muscle strength and pulmonary function in CP patients after respiratory training in addition to conventional rehabilitation. There is no consensus on the frequency, type or intensity of respiratory exercises for children with and adolescents with CP.