We describe five patients with severe nocturnal cough and daytime somnolence in whom the coughing attacks are triggered by assuming the supine body position. Quantity and quality of the nocturnal cough were evaluated in the sleep laboratory with and without nasal continuous positive airway pressure (N-CPAP). Air flow characteristics were assessed using flow volume and airway resistance loops. Airway anatomy was evaluated bronchoscopically. In all five patients, the cough had a barking quality. Flow-volume loops showed an expiratory collapse phenomenon in two of the patients. Endoscopically, all five patients had signs of airway collapse. All patients had difficulty falling asleep because of coughing and were awakened by it frequently. Sleep times ranged from 2.5 to 4.5 h per night. With N-CPAP pressures ranging from 5 to 13 cm H2O, all five patients had clinically significant improvement in their symptoms. Their sleep times increased to a range of 5 to 7.5 h per night and the daytime somnolence markedly improved or resolved. All five patients requested a N-CPAP unit for home use. We conclude that a cough that is predominantly associated with or exacerbated by the supine body position may be treated effectively with N-CPAP.