Petrikirche is a hall church in the High Gothic style, which approximates the ideal type of this church form. The building has a nearly square floor plan with a comparatively short choir.

St. Peter's Church, along with St. Reinoldi's Church and St. Mary's Church, is another medieval church located directly on Westenhellweg in Dortmund's city center. The three-bay structure was begun in 1322 and is made of sandstone. In its present form, the church once again displays the original, medieval form of the transverse gabled roofs above the side aisles. The elevated tower is striking; after its collapse in 1752, it was not seen in this form for a long time and was only rebuilt to its historic height in 1981, after the destruction of the Second World War.

Antwerp retable is the name given to a type of winged altarpiece produced for export, particularly in Antwerp workshops during the first third of the 16th century. Antwerp retables are generally characterized by their intricately detailed carvings, but also by certain standardizations, such as their dimensions and the frequent repetition of certain groups of figures. Over 200 examples are still preserved today in churches and museums in various European countries.

At 5.65 meters high and 7.40 meters wide with the double doors open, the Dortmund carved altar, the "Goldenes Wunder von Westfalen", is considered the largest surviving Antwerp altarpiece. The retable features two pairs of wings, the interior of which is also sculpturally carved.

The altar was originally commissioned by the Dortmund Franciscans from Jan Gillisz Wrage in Antwerp for their monastery church. After the monastery was dissolved during secularization, the St. Peter's congregation acquired the altar and brought it to their church. During World War II, the altar was removed and returned to Dortmund in 1954. It was restored in St. Peter's Church from the early 1960s onwards and reinstalled in 1985.

The winged altar is opened differently throughout the church year, revealing different images on the front.

From Thanksgiving to Holy Week and from Easter to Pentecost, the actual gilded carved altar with 36 compartments and a total of 633 gilded figures can be seen inside. It depicts the detailed story of Jesus' Passion, with the crucifixion at its center.