We present the case of a thirty-eight years-old man bearing of frequent crisis of asphyxiating wakefulness and breathnessless whenever he was asleep. There also were excessive daytime sleepiness and a strong snore before every wakefulness, but not for the rest of sleep. A polysomnographic study revealed normal values in the oxygen desaturation index, minimum oxygen saturation, an sleep structure alteration with a decrease of III-IV stages, high arousals index and RDI < 5. Pharyngeal diameters measured by mean of TC were normal, but sleepiness degree detected in the Epworth scale was high. Nasal fiberoptic endoscopy study allowed to see a swinging epiglottis that closed totally the upper airway during forced inspiration. The lack of desaturation episodes with numerous wakefulness along the sleep and excessive daytime sleepiness drove to the diagnosis of upper airway resistance syndrome (UARS). Treatment whit C-PAP just provoked an impairment in symptoms, but a CO2-laser partial epiglottectomy improved them. Patophysiological aspects of UARS, as well as its follow-up and therapeutic alternatives are commented.