In patients suffering from obstructive sleep apnea syndrome (OSAS) the reiterate injuries against the soft structures of the pharyngeal wall causes macro- and microscopic damages, which differ basically from the alterations verified in subjects without OSAS. We present a comparative histological study of 45 patients with OSAS operated on uvulopalatopharyngoplasties to face up 10 palates coming from normal post-mortem human among which a comparative anatomopathological study of 8 parameters was realized and the differences between the two groups signaled.