The article examines the orchestra of the Theatre of Dionysusand presents new observations about the Roman imperial phases of the monument. A thorough study of the decorative motifs of the marble pavement leads tothe identifation of two different phases: the first one can be linked to the transformations brought about by Tib. Cl. Novius in A.D. 61 - 62 , while the second is later. The marble parapet around the orchestra of the Theatre is also ascribed tothe phase of Novius. Furthermore, small holes in the pavement of the orchestrademonstrate that beast hunts were held in the Theatre, and a preliminary reconstruction of the protective grill around the orchestra is presented. The grill wasnecessary when gladiatorial games and beast hunts took place in the Theatre.Finally, some technical details demonstrate that in late periods the orchestrawas occasionally transformed into a waterproof pool for water spectacles.