The construction of the theatre probably dates back to the Hellenistic period, but the remains visible today belong to the Roman phase of the monument. Preserved are the concave with seven marble rows of seats, the orchestra, the floor of the stage building, and many elaborate architectural parts. The theatre has seven tiers and six steps seating up to 700, although as excavation is revealing the seating covers most of the hillside possibly seating three thousand spectators. The theatre is in the semi-circle fashion, with an orchestra, original meaning the spot where the choir and actors would appear. In Roman times the theatre was en-marbled, the original Greek theatre would have been full circle. Decoration and location of this theatre near the sea are similar to that of Ephesus (Asia Minor).
Milos enjoyed great cultural achievement, in the Hellenistic period, with the production of wonderful sculpture, in particular the Venus of Milos (Aphrodite), the imposing statue of Poseidon showing great sophistication. It is thought Venus (Aphrodite) may have graced the theatre as she was found nearby. Until recently moon lit performances and concerts were held, Shakespeare, Homer, Classical and modern music.