Habermas avec Žižek is a critique of Habermas's theory of communicative action, viewed through the lens of the theory of ideology formulated by Slavoj Žižek. By using the early notion of the Real, as a primordial repressed, developed by the early works of Žižek, this article claims that Habermas’s communicative rationality is the locus for a particular kind a delusion. This is a delusion that is constituted through a cynical rationality and a fantasy construction process, which, as ideological devices, operate not ‘by colonising’ but ‘by directly emerging’ from a ‘thin’ communicative rationality matrix. Furthermore, this ideological operation, taking place at the heart of a communicative matrix, is only visible when one rethinks a critique of ideology in which the Real appears as a universal but hypothetical truth from which the selfassumed transparent Habermasian consensus is problematised.