The combination of chronic lung disease and OSA in a single patient is still, as yet, poorly understood. Many research and clinical questions remain, including how best to quantify upper airway collapsibility and sleep fragmentation in patients already at risk for hypoxemia caused by chronic lung disease. These questions must be answered given the high prevalence of the OVS, COPD and OSA, and observational cohort studies that show very high mortality without OSA treatment. Other chronic lung diseases, such as IPF, are much less common; yet diagnosis and treatment of OSA may be important. Within these patient populations, there are few or no therapies available to target the underlying disease and its consequences. Recognition and treatment of OSA, therefore, could offer key benefits, such as improvements in quality of life or fatigue level. © 2014 Elsevier Inc. All rights reserved.