Chronic Obstructive Pulmonary Disease (COPD) is usually characterized by a progressive decline of lung function. We reported the 10 years follow-up of an elderly man, a heavy smoker with severe COPD and apical bullous emphysema. During 6 months pulmonary rehabilitation program the patient's clinical state improved significantly and it associated with a steep increase in forced expiratory volume in one second (FEV1). This case report elaborates on the unexpected gain of FEV1 in the follow-up of a COPD patient.