Visual smog has been recently presented as a pressing problem of majority of settlements in Slovakia and abroad. The aim of the thesis is to clarify the ways of environmental degradation by visual smog. Based on the thesis’ objective, explanation of „visual pollution“ terminology, the impact of external advertising on human life, aesthetic impact of advertising media as well as advertising content and ethical impact are included. The important aspect of visual smog is also an architecture and cultural monuments and their cultural and historical context for outdoor advertising, presence of outdoor advertising in the protection zones of parks, protected areas and at their orders and, also, the influence of billboards on road safety and smoothness and drivers' distraction in electronic advertising or illuminated advertising. In Master thesis, we present the legislative framework of visual smog in Slovakia and in the world using the examples from the world of limiting outdoor advertising in cities and highways together with examples of the absolute advertising ban. Finally, we consider the proposals for mitigation measures of the visual smog negative impacts on the environment.