Abstract. In political persuasion the persuader, beside bearing logical arguments and triggering emotions, must present one's own image (one's ethos) of a credible and reliable person, by enhancing three dimensions of it: competence, benevolence and dominance. In a parallel way, s/he may cast discredit on the opponent by criticizing, accusing or insulting on the same three dimensions. The work provides a description and a typology of multimodal discrediting moves focusing on the discrediter's multimodal behavior. Based on an Italian corpus of political debates the analysis points out which facial expressions, gaze behavior, gestures, postures and prosodic features are used to convey discredit concerning the three target features of competence, benevolence and dominance. The qualitative study of discredit signals highlights the close relation with emotions and in this sense particular attention is given to them as triggers of the Audience's evaluation