NPPV is a major advance in respiratory and critical care medicine. In the acute setting, it has a clear role in the management of patients with COPD who are acidotic, and in weaning from IMV. NPPV in hypoxic RF shows promise for selected patients, but further studies are required. For domiciliary use, NPPV is effective in both the short and long term for the management of extrapulmonary restrictive disease, but further research is required for COPD.