Commonly, tectonic windows have very complex structures, exemplified by the Tauern Window (TW) in the European Eastern Alps. Its complex folded nappes were formed during several deformation phases since the early Cenozoic. The final phase (Miocene) was driven by the indentation of the Dolomites indenter (DI), which heavily shaped the structure of the TW, especially its western end. Here, exhumation took place along the west-directed, viscous Brenner normal fault (BNF). However, the structure and geometry of the western TW is not completely deciphered, although it provides insights into its Miocene deformation history. Our aim is to unveil its structure by constructing a 3-D model using the software MOVE^TM. We compiled and analyzed published geological maps, cross-sections and structural data, and modelled three tectonic horizons and the viscous BNF by applying inter- and extrapolating methods. Our analysis shows that the antiforms of the western TW deformed differently. The almost cylindrical shape of the Tuxer antiform deviates from the non-cylindrical Zillertaler antiform. This variation is linked to the proximity and asymmetry of the DI, suggesting initially uniform structures were deformed by the indenter and the associated reorganization of the lower crust. Comparing fold axes orientation with the dip of the viscous BNF, we found that the latter’s influence zone ranges between 3 and 4 km in its footwall. The Schöberspitzen antiform likely developed pre- or synkinematic to the viscous BNF, as its fold axis orientation correlates with the BNF’s dip.