The auditorium comprised three rows of stone seats, amphitheatrically arrayed and divided into three tiers accommodating 100 persons. Through an underground passage, the auditorium was connected to the adjacent Theatre where the "Ekklesia of demos", the citizens assembly gathered. The architectural connection of the two edifices and their location close to the Agora, suggest their identification as the administrative centre of the city. The plan of the Bouleuterion closely follows the pattern of the Bouleuterion at Miletus.

Remains of the rows of seats, the foundation and parts of the interior walls are still visible today.