The role and the legitimacy of fiction during the 16th and 17th century sparked an intense debate. Numerous indications suggest that indifference about the mixing of exact history and imaginary facts becomes a more and more dated attitude at the end of 16th century. I will examine three different cases: an epic by Luis de Zapata, Carlo famoso (1566), The Agatonphile by Jean-Pierre Camus (1620) and Gilles Ménage's annotations of Tasso's Aminta. The question of distinguishing fact from fiction in these works appears as particularly urgent and interacts with interpretation on several levels. This question asks that one identify, in more or less explicit ways, the criteria of the fictitious in the texts; furthermore, all three authors would like to impose on their readers a proper interpretation of their work, or the work of Tasso in the case of Ménage. What are the motivations, the conceptual means and the results of these three authors' attempts to highlight the status of their work, and consequently, the very nature of fiction?