The contested and porous border between fact and fiction has been, for the past 40 years, a favoured point of departure for many contemporary theoreticians of fiction (such as Genette, Pavel, Schaeffer, Lavocat) who try and understand fiction not only as a literary genre but as an operative category. What I want to do in this paper is to apply some of their conclusions to a contemporary widespread phenomenon in popular culture that is not only a manifestation of a current paradoxical distrust of fiction (erosion of the romanesque process cf. Binet, Tel Quel) and the ways in which that phenomenon fuels such distrust. This paper thus aims to investigate the function and effect of the heading or tagline occasionally placed at the beginning of a work of fiction that reads: ‘based on a true story’ or ‘based on actual events’. To circumscribe my analysis, I have chosen to focus on the use of this tagline in recent American popular cinema (Hollywood films), where it is most obvious and I will base my description on films that explicitly state (either at the beginning or at the end) that they are based on a true story.