[The work of Hunayn ibn Ishāq in the Arabic manuscripts of Escurialense Library].

After a short historical introduction about Hunayn's life and about the foundation and development of the Escurialense Library, the article deals with the Arabic collection which is kept in it. Hunayn is the author of some work in the Escurialense codices, and the translator of some others. Particularly, three codices containing original medical works by Hunayn are listed here and commented on in detail, together with twenty-five containing Hunayn's translations of Hippocratic and Galenic texts. Some astrological texts are also treated.