Lung volume reduction surgery (LVRS) has been demonstrated to improve lung function, exercise tolerance and quality of life. However, the duration of improvement is unknown. While the maximal duration of improvement cannot be determined at this time due to an inadequate period of follow-up, we have observed in some patients significant and relatively rapid declines in gains following LVRS. We describe 6 patients who increased FEV1 by at least 10% of the predicted value after LVRS and subsequently experienced rapid loss of the increment in FEV1 (mean loss 79%, 95% CI 58-100%) over a period ranging from 14 to 20 months following surgery.