Neuromuscular and chest wall diseases include a diverse group of conditions that share common risk factors for sleep-disordered breathing, including respiratory muscle weakness and/or thoracic restriction. Sleep-disordered breathing results from both the effects of normal sleep on ventilation and the additional challenges imposed by the underlying disorders. Patterns of sleep- disordered breathing vary with the specific diagnosis and stage of disease. Sleep hypoventilation precedes diurnal respiratory failure and may be difficult to recognize clinically because symptoms are nonspecific. Polysomnography has a role in both the diagnosis of sleep-disordered breathing and in the titration of effective noninvasive positive-pressure ventilation.