The paper presents textbooks published by the Prešov publishing houses in the first three decades of the 20th century. It shows an increase in the number of textbooks published in Slovak language, especially after 1918. The paper focuses on prints – textbooks, especially from the field of humanities and natural sciences, published in the Slovak language (early 20th century form of language) or local dialect, by the Prešov publishing houses of A. Kósch or J. Štehr, printing company of Saint Nicolaus or Pallas. The textbooks were used by pupils and students as well as a new generation of teachers. The paper presents an analysis of the documents not only in terms of their content but also of book culture, taking into account former owners.