The hypopharyngeal diverticulum is rare because it usually occurs old age and has no specific symptoms until grow significant size. But the clinician must be concerned about it because of increase of old age group and probability of increase of the incidence. Numerous theories for pathogenesis of hypopharyngeal diverticulum were reported, but two theories were accepted until now. One is pulsion theory that a limited region of the wall of hypopharynx loses its power of resistance against the intraluminal pressure. The other is incoordination theory that all patients with a diverticulum has an abnormal temporal relationship between pharyngeal contraction and cricopharyngeal relaxation and contraction. Recently, authors experienced a case of hypopharyngeal diverticulum and report briefly with literature.