The sleep apnea-hypopnea syndrome (SAHS) in the elderly is not rare. The pathogenesis and clinical manifestations have the characteristics specific for the elderly. The diagnosis criteria are also different with those of the non-elderly. The complications are usually more serious. Continuous positive airway pressure is the first choice for the treatment. In this paper, we reviewed the prevalence, the pathogenesis, the clinical manifestations, the diagnosis criteria, the complications and outcomes, and the treatment of SAHS in the elderly by comparing with those in the non-eldelry.