Question: Can a session of exercise with incorporated expiratory manoeuvres substitute for a session of breathing techniques for airway clearance in children with cystic fibrosis? Are children with cystic fibrosis as co-operative and satisfied with the exercise regimen as with the breathing techniques? Design: Randomised, cross-over trial with concealed allocation and intention-to-treat analysis. Participants: 34 children with cystic fibrosis in a stable clinical state. Interventions: Participants underwent two 20-min airway clearance interventions on two scheduled clinic days: one involving three bouts of various whole-body exercise modalities each followed by independent expiratory manoeuvres, and the other involving breathing control, thoracic expansions with manual expiratory compressions, and the forced expiratory technique. Outcome measures: Wet weight of expectorated sputum, change in lung function, co-operation with treatment, perceived treatment quality, and satisfaction with treatment were all assessed after each intervention. Results: The wet weight of sputum after exercise was 0.6 g higher after the exercise intervention, which was not statistically or clinically significant (95% CI -0.2 to 1.4). However, lung function and participant satisfaction with the treatment were both significantly better after the exercise intervention. Co-operation with treatment and perceived treatment quality were equally high for each intervention. Conclusion: A session of various whole-body exercises interspersed with independent expiratory manoeuvres could be an acceptable substitute for a session of breathing control, thoracic expansions with manual expiratory compressions, and the forced expiratory technique in children with mild cystic fibrosis lung disease. Trial Registration: NCT01509235. [Reix P, Aubert F, Werck-Gallois M-C, Toutain A, Mazzocchi C, Moreux N, Bellon G, Rabilloud M, Kassai B (2012) Exercise with incorporated expiratory manoeuvres was as effective as breathing techniques for airway clearance in children with cystic fibrosis: a randomised crossover trial. Journal of Physiotherapy 58: 241-247]