The paper begins by explaining the concept of politeness, which first entered into a field of pragmatics when Brown and Levinson introduced an exhaustive politeness framework which later served as a basis for various research in this area. These linguists based their postulates on Grice’s Cooperative Principle and Leech’s conversational maxims. Their theoretical concepts prompted Cupleper’s further research in the field. Culpeper focused his research on impoliteness as a term as equally relevant as politeness. Even though the basis of his taxonomy were Brown and Levinson’s principles, he later modernized and adapted it according to Spencer-Oatey’s Rapport management model, which served as a framework for the research. After setting up the framework for the thesis, the role of Twitter in contemporary political communication is explained, followed by the explanation of the methodology used. The main part of this thesis deals with the pragmatic analysis of impoliteness in Trump’s tweets before and after the 2016 US presidential election using Culpeper’s impoliteness strategies as a research base. In order to analyze his tweets, we created a table consisting of 92 tweets selected by keywords over a period of 6 months before the election and 6 months after the election. The table is based on the elements that were repeated in the data as well as on Culpeper’s impoliteness super strategies, Spencer-Oatey’s rapport management categories and most common impoliteness triggers. The final version of the table has eleven categories. The analysis of the results leads us to conclude that Donald Trump is using his powerful status to humiliate and insult political opponents and celebrities who opposed him during and after the campaign. The way of communicating on Twitter did not change much after he became president, so we conclude that Trump's unique style of communication is present both before and after the election, and that both men and women are targeted, which depended mostly on current topics and issues addressed by the president.