According to some authors, he was descended from Jews forcibly converted to Catholicism after 1492, and one of his forebears had been burned by the Inquisition for secretly continuing to practice Judaism.

In 1599, he published the first part of Guzmán de Alfarache, a celebrated picaresque novel which passed through no less than sixteen editions in five years; a spurious sequel was issued in 1602, but the authentic continuation did not appear until 1604.

[3] In 1571, Alemán married, unhappily, Catalina de Espinosa, and was constantly in money difficulties, being imprisoned for debt at Seville at the end of 1602.

[3] In addition to the works already mentioned, Alemán is the author of a life (1604) of St. Anthony of Padua, and versions of two odes of Horace bear witness to his taste and metrical accomplishment.

His most famous work, however, is Guzmán de Alfarache, which was translated into French in 1600, into Italian in 1606, into German in 1615, into English in 1622 by James Mabbe, and into Latin in 1623.