Szymon Rudnicki was bishop of Warmia from 1604 to 1621. He continued the post-Tridentine reform of the Church after his predecessors, as documented above all in official and liturgical prints. These are stored in the largest number in the collection of the Library of the Warmian Metropolitan Seminary ‘Hosianum’ in Olsztyn. The present study, carried out by introducing descriptions and histories of old prints related to the figure of the bishop – portrays him as a bibliophile and a zealous diocesan governor. One volume from the book collection of Bishop Rudnicki, the 1610 synod constitutions, liturgical agendas, as well as the 17th century biographies of the hierarch and two variations of his coat of arms are discussed.