Noninvasive positive pressure mechanical ventilation (NIPPV) in exacerbated chronic obstructive pulmonary disease (COPD) has been investigated early and after 1 yr of follow-up.To this end, 30 patients were enrolled in a prospective, controlled trial: 15 had early administration of NIPPV (Group A), 15 had medical therapy only (Group B); assignment was made on the basis of equipment availability only.In-hospital mortality, need for endotracheal intubation and mean length of hospitalization were lower in Group A, though the difference was not statistically significant. Arterial oxygen tension in arterial blood (Pa,O 2 ), carbon dioxide tension in arterial blood (Pa,CO 2 ) and HCO 3 -improved significantly in both groups from admission to discharge: 45. -up, 3, 6, and 12 months survival rates were significantly higher in Group A than in Group B (p<0.02). Hospital new admissions over 1 yr were more frequent in Group B (n=6, incidence rate: 0.216%) than in Group A (n=4, incidence rate: 0.084%).Therefore, noninvasive positive pressure mechanical ventilation may be added to "conventional" medical therapy in exacerbated chronic obstructive pulmonary disease. Eur Respir J 2000; 15: 98±104.