Long before the post-truth concept became popular, the aftermath of the Smolensk Catastrophe in Poland, in which 95 high-ranking Polish officials died in a plane accident, saw the emergence of a conspiracy-narrative of the like promoted by the Law and Justice party. Then in opposition, now the incumbent party - Law and Justice - promotes a conspiracynarrative of the plane crash, by denying official accounts, whilst talking about revealing the “only truth”. In factual terms, it can be said that the Smolensk Catastrophe, was caused by the combination of pilot error and unfavourable weather conditions, as proved by a vast amount of evidence. Yet, half of the public opinion in Poland disbelieves the official findings of the investigation, and half of those citizens even believe it was a premeditated assassination. Since then, Law and Justice has consolidated a core group of followers, perhaps even “believers”, who have been taking to the streets to support the idea of revealing the “Smolensk Truth”, although with much less intensity since 2017, as the political salience on the issue has waned. On the opposing side, a great number of citizens still follow the accident narrative provided by the former government (Civic Platform), constructed upon the opinion of the official investigation’s experts. Thus, each side of the conflict has its own experts, and it’s the public’s perception of these experts combined with politicians that feeds further mistrust and alienates great swathes of Poland’s citizens, creating a place for post-truth play. The aim of this thesis is to analyse the frames’ construction of the political reality that surrounded the case of the Smolensk Catastrophe, the plane crash that turned into a deeply political issue in Poland. The study answers the following questions: How, and in what way, have Polish politicians instrumentalised a national tragedy (in this case, the crash) to mobilise electoral support, sway voters, and define their politics? What kinds of mechanisms have affected a frame’s strength, and what is the narrative of the post-truth politics of the Smolensk crash? The Smolensk Catastrophe debate did not trigger a governmental change in Poland, due to the fact that during the parliamentary campaign politicians abstained from commenting on conspiracy theories in order to show their moderate face; yet the Smolensk Catastrophe debate has revealed something intriguing: how a shared belief in a particular  conspiracy theory can play a role previously reserved for religion or ideology, in serving as an indicator of political identity. The research questions are answered through frame analysis. The data comes from newspaper mix-method content analysis, which I conducted over a five-year period. The analyses reveal the existence of three main frames, of which one is a conspiracy frame supported by the nowincumbent Law and Justice party, the second one is the accident frame supported by journalists, the former government (Civic Platform) together with public officials, and the third one is the political instrument frame promulgated mostly by journalists. The main political actors strategically introduced the Smolensk Catastrophe’s discourse into their narratives, polarising Polish society, with old conflicts gaining a new dimension. The study contains salient information not only with regards to the understanding of the creation of conspiracy theories narratives, but also for the field of framing research. Further research could be undertaken to identify other factors that influence the frame’s strength.