Background Patients with COPD reduce physical activity to avoid the onset of breathlessness. Fan therapy can reduce breathlessness at rest, but the efficacy of fan therapy during exercise remains unknown in this population. The aim of the present study was to investigate 1) the effect of fan therapy on exercise-induced breathlessness and post-exercise recovery time in patients with COPD and 2) the acceptability of fan therapy during exercise; and 3) to assess the reproducibility of any observed improvements in outcome measures. Methods A pilot single-centre, randomised, controlled, crossover open (nonmasked) trial (clinicaltrials.gov NCT03137524) of fan therapy versus no fan therapy during 6-min walk test (6MWT) in patients with COPD and a modified Medical Research Council (mMRC) dyspnoea score ⩾2. Breathlessness intensity was quantified before and on termination of the 6MWT, using the numerical rating scale (NRS) (0–10). Post-exertional recovery time was measured, defined as the time taken to return to baseline NRS breathlessness score. Oxygen saturation and heart rate were measure pre-and post-6MWT. Results 14 patients with COPD completed the trial per protocol (four male, 10 female; median (interquartile range (IQR)) age 66.50 (60.75 to 73.50) years); mMRC dyspnoea 3 (2 to 3)). Fan therapy resulted in lower exercise-induced breathlessness (ΔNRS; Δ modified Borg scale) (within-individual differences in medians (WIDiM) −1.00, IQR −2.00 to −0.50; p<0.01; WIDiM −0.25, IQR −2.00 to 0.00; p=0.02), greater distance walked (metres) during the 6MWT (WIDiM 21.25, IQR 12.75 to 31.88; p<0.01), and improved post-exertional breathlessness (NRS) recovery time (WIDiM −10.00, IQR −78.75 to 50.00; p<0.01). Fan therapy was deemed to be acceptable by 92% of participants. Conclusion Fan therapy was acceptable and provided symptomatic relief to patients with COPD during exercise. These data will inform larger pilot studies and efficacy studies of fan therapy during exercise.