The Roman theatre of Misenum is at present situated below a modern building which constituted a severe limit to its fruition, prior to the excavation aimed at valorising the monument. The visible parts of the ancient structure comprised most of the middle ambulatory, a small section of the upper one and some remains of the attic walls of the _summa cavea_ (the latter situated on private property). The excavation and arrangement involved both the interior and exterior of the monument. In the interior four trenches were dug revealing a complex stratigraphy which filled almost half of the middle tunnel and documented a sequence of small occupation levels and layers of accumulated material that had formed between the mid 5th and the end of the 7th century A.D. In only one of the trenches was it possible to document the monument’s original occupation layer, which in its lower part was below the level of the water table. The section of the theatre’s paving, made temporarily visible by the use of pumps, was in _opus signinum_. The structures relating to the ambulatory of the theatre were cleaned and the solid facings in _opus latericius_, with pillars supporting cross-vaults, rendered clearly visible. These structures probably date to the beginning of the 2nd century A.D. The excavation on the exterior, undertaken with the aim of creating an independent entrance for the monumental complex, revealed the collapse of the large cruciform pillars situated at the entrance to the parados and traces of a late antique necropolis which overlay the collapse. The theatre entrance was created by passing through the original western entrance (parados), thus restoring its original function. During construction of the curtain wall the remains of a road came to light, flanked by rooms ( _tabernae?_ ) and probably relating to the public part of the city.