BACKGROUND: This study investigated whether descriptors of breathlessness differed after participation in an 8 week pulmonary rehabilitation program and whether changes in sensory quality would be reflected in responsiveness to pulmonary rehabilitation. METHODS: People with COPD provided descriptors for their sensation of breathlessness before and after an 8 week pulmonary rehabilitation program. Primary outcomes for responsiveness to pulmonary rehabilitation were the 6 minute walk distance (6MWD) and the St George Respiratory questionnaire. Significant proportional shifts for sensory categories after rehabilitation were identified using the McNemar test. Random effects mixed modeling was used to determine significance of differences for primary outcomes between subjects modifying or not modifying descriptors of breathlessness. RESULTS: Of the 107 people referred to the pulmonary rehabilitation program, 94 met the spirometric criteria for COPD, with 58 having data for pre and post assessments (36 males, 71 ± 9 years old, percent of predicted FEV1 58 ± 24%). A significant proportion of subjects reduced descriptors of air hunger (P =.03, odds ratio 0.31, 95% CI 0.09-0.89) and depressed, regret, helpless (P =.04, odds ratio 0.36, 95% CI 0.10 -1.05) following rehabilitation. Subjects reducing their use of descriptors of air hunger had greater improvements in the 6MWD after rehabilitation (P =.006, mean increase 46 m). CONCLUSIONS: The sensory quality of breathlessness was modified for approximately one third of subjects after pulmonary rehabilitation, with significant improvements in the 6MWD for subjects who reduced their use of descriptors of air hunger.