The church, which is oval in plan, is preceded to the west by a semi-circular narthex. Inside, twin columns placed in front of the walls support the capriciously cut-out cornice and the wooden vaulting with its flattened profile;this defines a second interior volume where the light from the windows and the oculi is cleverly diffused both directly and indirectly. To the east, a long deep choir is surrounded by an upper and a lower gallery.
The prodigious stucco decoration is the work of Dominikus Zimmermann, assisted by his brother Johann Baptist, who was the painter of the Elector of Bavaria, Max-Emmanuel, from 1720. The lively colours of the paintings bring out the sculpted detail and, in the upper zones, the frescoes and stuccowork interpenetrate to produce a light and living decor of an unprecedented richness and refinement. The abundance of motifs and of figures, the fluidity of the lines, the skilful opening of surfaces, and the 'lights' continually offer the observer fresh surprises. The ceilings, painted as trompe-l'œil, appear to open on an iridescent sky, across which angels fly;these, too, contribute to the lightness of the whole.
Moreover, the preservation is perfect: the colours have retained all their freshness and nothing is lacking in the Rococo whole that is Wies - the splendid asymmetrical ironwork of the choir, the pews of sculpted wood for the faithful, the pulpit, and the elegant and amply modelled saints that inhabit the architecture.