ENThe article focuses on Matiasz Czyżewski’s book „Alkoran” (1616), published probably in Vilnius and directed against the local Muslim community of the Lithuanian Tatars. This rare edition remains basically unknown, although its complete copy is kept in the Gdańsk Library of the Polish Academy of Sciences. The content of the book is compared with the textually related somewhat later Piotr Czyżewski’s pamphlet entitled „Alfurkan tatarski” (Wilno, 1616/1617), which was published several times and therefore is well known to the specialists in the history of Christian-Muslim relations in the Grand Duchy of Lithuania. Particular attention is paid to Matiasz Czyżewski’s second main section (chapter), which outlines the misdeeds of the Lithuanian Tatars, mentioning a significant number of persons and events related to the history of the local Tatar community, which makes it an important historical source. After a general description, the full text of this particular chapter of „Alkoran” is given in modern Polish spelling. Key words: Grand Duchy of Lithuania, polemical literature, early printed books, Lithuanian Tatars, Matiasz Czyżewski. [From the publication]