<p>The present study examined the persuasive impact of conspiracy theories (CTs) in relation to two distinct communicative strategies: argumentation and narrative. The final sample consisted of 160 participants, randomly assigned to three groups: a first group (N = 56) watched a video in which a conspiracy theory related to the Chernobyl nuclear power plant explosion was presented in a predominantly argumentative form (mostly argumentative group: MAG); a second group (N = 53) who watched a video in which the same conspiracy theory was presented in a predominantly narrative form (mostly narrative group: MNG); and a third control group (CG) (N = 51) who watched a video on non-conspiracy topics. The experiment was conducted online by the participants. The scores obtained on the Generic Conspiracist Beliefs (GCB) scale (Brotherton et al. in Front Psychol 4:279, 2013) at T0 (before exposure to the persuasive message) and T1 (after exposure) in three groups of participants were evaluated. Furthermore, the level of education, subclinical psychiatric symptoms (depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism), paranoid persecution, and paranoid reference, as well as the level of transportation, were also assessed. The primary findings indicated that there was a greater endorsement of conspiratorial beliefs at T1 than at T0 in the MAG. In contrast, no change was observed in the total score of the GCB scale at T1 compared to T0 in the MNG. However, in the MNG there was an increase in one subscale of the GCB, which related to government malfeasance. Overall, these results indicate that both conspiracy arguments and conspiracy narratives can influence audience beliefs. However, argumentation appears to have a more pronounced effect than narrative.</p>