Prevalence of sleep apnea syndrome in patients with acromegaly is about 70%. It seems that comorbidities of arterial hypertension or type 2 diabetes are more severe in patients with acromegaly and sleep apnea syndrome. Besides sleep apnea syndrome associated to acromegaly gives rise to few symptoms, that explains it is under diagnosed. The mechanisms of the association are based on maxillofacial modifications linked to acromegaly, a thickening of soft tissues with deposits of glyco-aminoglycanes but probably also because of the associated obesity, of the potential existence of a goiter and a muscular dystrophy of the dilatative muscles of the pharynx.