In 1743 the decoration of the chapel was relatively simple, and Maria Theresa employed renowned artists to give the chapel a new prestigious interior. The marble high altar with side pilasters, finished with a rounded gable, was probably designed by Nikolaus Pacassi, and is crowned by a gilded sculpture of the Holy Trinity, which was executed by Franz Kohl, a pupil of Georg Raphael Donner.
Paul Troger, one of Austria's foremost baroque artists was commissioned with the altar painting showing the marriage of the Virgin Mary. The altar table, with adoring angels to the sides, holds a large marble tabernacle in the form of a tempietto, the door of which is decorated with a gilded relief of a Pietà.
Two further altars are situated on the wall on each side of the chapel. The paintings show the education of Mary and Saint John of Nepomuk,
and are both by the Venetian painter Giovanni Battista Pittoni, who was employed in many European courts.
The other two altars were created as framed niches and each houses a gilded lead statue: the suffering Madonna and John the Baptist, both of which were executed by Franz Kohl. The ceiling paintings are by Daniel Gran, another leading figure in Austrian baroque art, and show Mary Magdalene surrounded by allegorical representations of the cardinal virtues: faith, hope and charity.
The consecration of the palace chapel took place on 29th April 1745 and was conducted by the Archbishop of Vienna, Count Sigismund Kollonitsch. The chapel was originally dedicated to Mary Magdalene, but with its refurbishment it was dedicated instead to the marriage of the Virgin Mary.