The church of SS Peter and Paul has three naves – the main naves and two aisles – which provide access to chapels with very valuable ornamental altars.
The most captivating are mainly the Gothic Revival altars: the main altar of SS Peter and Paul; the side altars at the rainbow, i.e. the altar of St Joseph and the altar of Our Lady of the Rosary; as well as the altars in the aisles of St Barbara, Our Lady of Perpetual Help, Our Lady of Częstochowa, and the Most Sacred Heart of Jesus.
Aside from the Gothic Revival altars, the church in Namysłów also has a number of Late Baroque altars of St Peter of Alcantara, the Queen of Angels, and the Passion of Christ.
The altar of St Peter of Alcantara, dated to around 1720, can be found in the second southern chapel from the west. Originally located in the Franciscan church, the altar has a contemporary oval painting of St Peter of Alcantara. It is decorated with the statues of St Apollonia, St Catherine and several angels, and on top of the altar there is a painting of St Sebastian.
In the second northern chapel from the west, you can find an altar whose centrepiece is a shell-shaped alcove with a Gothic statue of Madonna with Child, dated to around 1410. This altar too has statues of angels, a group sculpture on top of the Adoration of Our Lady of Loreto, and the figures of King Herod and a soldier killing an infant.
The most valuable altar in the church of SS Peter and Paul can be found in the first northern chapel from the west. Built in 1720 by the famous Silesian sculptor Georg Leonhard Weber, the altar of the Passion of Christ is an accurate copy of the altar in Świdnica, which is dated to 1709. Its centrepiece is a life-sized scene from Gethsemane, and a relief depicting the Fall under the Cross.