Hypopharyngeal diverticulum, also known as Zenker's diverticulum, was first described by Ludlow in 1764. It is a posterior herniation of hypopharyngeal mucosa most commonly through Killian's triangle just proximal to the cricopharyngeus muscle, a component of the inferior pharyngeal constrictor.

Cricopharyngeal dysfunction, suspected but as yet not proven to be the cause of diverticulum formation, is assumed to be etiologic; hence, cricopharyngeal