The facade of Saints Peter and Paul Basilica was constructed with dolomite. It resembles that of the Church of Santa Susanna in Rome by Carlo Maderno, but also, it contains similarities with the facade of the main Jesuit church of Il Gesł. In its niches are statues of Jesuit saints: Ignatius of Loyola, Francis Xavier, Aloysius Gonzaga, and Stanisław Kostka made by Dawid Heel. Above the main portal, there's the emblem of the order of Jesuits with saints Sigismund of Burgundy and Ladislaus I of Hungary. The church interior has a broad, single-nave with two aisles consisting of chapels, as well as the transept with a dome at the intersection, and a short rectangular chancel around the altar, with semicircular apse covered with a hemispherical vault.In front of the Church-grounds there are several plinths with raised sculptures of apostles designed by Kacper Bażanka. They were made with Pińczów limestone, and completed in 1722 by Dawid Heel. Today, in place of the original 18th century statues, which were very much damaged by acid rain, there are contemporary copies made of the same material by Kazimierz Jęczmyk