SummaryThe grammar, dictionary, and religious texts by Friar Juan Baptista de Lagunas (c.1530–1604) are three works that the author conceived as complementary and published within one cover (1574). Nevertheless, the content of each book is rather different in the theme developed and the influences that oriented its realization. The works of the French Franciscan monk Maturino Gilberti (c.1498–1585) had a great impact on all three texts; theArtein particular. Lagunas’ dictionary, however, follows Ambrogio Calepino (c.1435–1511), while his doctrinal texts are guided by Catholic religious teachings. Furthermore, each of the three texts has its own pagination. Despite these details, the unity of the three texts as one single volume can be shown by the textual coherence achieved through the cross-references between them and by the printing decisions taken at the moment of production, both factors that strengthen the argument supporting the intertextual unity of Lagunas’oeuvre.