During the Spanish Golden Age, in literary texts, we can find a lot of proverbs, precepts, maxims, apothegm considered as the result of an interest in popular and bookish culture and, at the same time, as a consequence of a display of erudition. You can also find the above mentioned phraseological units in the picaresque novel. The aim of this work is, for this reason, to analyze the purpose and the characteristics concerning these units considered like a treasure coming from the popular knowledge in Gregorio González’s work titled, El guitón Onofre (1604?). This novel plays an important role in the picaresque novel from a thematic, structural and chronological point of view. In addition, compared with other novels it contains a great variety of proverbs. The author explains the main character’s life thanks to the use of proverbs that he modifies as he likes.