The form of spirit possession performed by practitioners who are readily initiated into Dominican Vodou requires them to be excellent (inter-)actors, dancers, and poets. The article focuses on the ritual practice of spirit possession in the Southwest of the Dominican Republic with emphasis on the question as to what constitutes effectiveness of spirit performance and how it is produced. The authors do so by drawing upon videographic data created for methodological purposes within the context of a larger project on the “Modes and Function of Spirit Possession”, funded by the Austrian Science Fund, and archived at the Phonogrammarchiv of the Austrian Academy of Sciences, as well as on interviews with performers. A specific focus is devoted to the construction of authority, that is by what means a spirit possession episode is recognised by peers as truly mandatory in the sense of the messages it conveys. Among factors that are directly linked to successful ritual performance are a careful orchestration and execution of the event, a display of deep emotional immersion into the spirit character and a correlation with some minimum standardised forms. However, we found that authority is also constructed through aspects outside the ritual framework such as a medium’s socio-economic status and moral lifestyle, as well as her standing in good terms with peers. Only on top of that can the performance by itself condense all directly linked factors into an authoritative manifestation of a spirit in the human world.