The paper is a presentation of research on the preaching activity of the Wrocław Dominicans in the late Middle Ages. It will answer the questions of who, when, where, to whom, and what sermons were preached. This requires both a discussion of the legal framework of Dominican preaching and prosopographical studies on the education and careers of individual preachers, as well as a presentation of the preaching materials from the library of the Wrocław priory.