The thesis deals with the problem of the importance of non-verbal communication in public speaking. Non-verbal communication is often mentioned as a key factor in the perception of the quality of a public performance and, for the purposes of this thesis, a research question is asked to determine to what extent the audience consciously receives and perceives non-verbal signals, to what extent they affect the audience’s perception of quality, and whether the audience has the ability to correctly interpret non-verbal communication. A specially prepared questionnaire was used for the research, which the respondents filled out after watching a part of Donald Trump's inaugural speech. This politician was chosen because of his specific and emphasized presentation of non-verbal signals. The results showed that non-verbal signals that an individual sends to the audinece in a public performance significantly affect the audience’s perception of quality, but, at the same time, when asked about a specific element from the observed example, most do not recognize non-verbal elements.