Background. Pulmonary rehabilitation is recognised as an effective treatment in reducing disability and improving the quality of life in patients with COPD. We evaluated the effects of a course of pulmonary rehabilitation in improving the physical performance and lung function in patients with or without COPD exacerbations. Methods. 74 patients with COPD were enrolled, 37 (24 males and 13 females, mean age 74.6 years) without exacerbations (group A), and 37 (23 males, 14 females, mean age 73.9 years) with exacerbations (group B). The latter must have had the latest exacerbation at least one month before the inclusion. All patients underwent to a rehabilitation programme of 8 visits in 4 weeks in a day-hospital setting, with exercise training, respiratory muscle training and education on COPD. The changes in physical performance and lung function in respect to baseline were measured by a 6-minute walking test, using phethysmography, and by an analogic manometer measuring maximal inspiratory and expiratory pressures (MIP, MEP). Results. Patients of group A showed a mean increase in timed walk distance of 58.38 ± 57.46 m, compared to a mean increase of 31.38 ± 44.78 m in group B patients (p = 0.028). As to lung function, a mean increase of 178.92 ± 132.28 ml in FEV1 in group A versus 67.84 ± 102.04 ml in group B (p < 0.0001) and a mean increase of 22.36 ± 25.06 cm H2O in MEP in group A versus 7.70 ± 12.28 cm H2O in group B (p = 0.002) was found. Conclusions. These findings indicate that patients with COPD with exacerbations achieve a less favourable outcome of pulmonary rehabilitation, with a significantly lower improvement of physical performance, respiratory muscle strength and lung function in respect to subjects without exacerbations.