Diploma thesis deals with the issue of ethics in advertising. The work is divided into two parts - theoretical and practical. The theoretical part deals with the definition of concepts such as ethics and advertising, the importance of and their interdependencies. Furthermore, this section deals with the legislative definition of advertising, its regulation and self-regulation. The practical part as a theoretical specific examples of ads that are deemed unethical or illegal. The aim of the thesis is to determine the impact of ethics on advertising in the Slovak and Czech Republic, based on the analysis and assessment of the individual complaints submitted to the Advertising Board, and to try to define the boundaries between ethical and unethical advertising so that it can serve as a tool for creating advertising in accordance with law and ethics.