Diseases of the lung can interfere with normal healthy sleep in many ways. Pulmonary function deficits lead to gas exchange abnormalities resulting in sleep-related hypoxemia or alveolar hypoventilation. Sleep may also be disturbed by other factors in these patients, such as, e.g., nocturnal cough and dyspnea. Finally, some bronchopulmonary disorders show complex and sometimes bidirectional relationships with sleep apnea. The sleep disorders associated with lung diseases may lead to symptoms such as poor sleep quality, daytime fatigue and sleepiness, and reduced quality of life. Diagnostic procedures include pulse oximetry, capnometry, and poly(somno)graphy. Apart from therapy of the underlying lung disease, treatment primarily consists of oxygen supply, noninvasive ventilation, and continuous positive airway pressure (CPAP) therapy.