The topic of this thesis is the impact of the COVID-19 pandemic on small and medium-sized enterprises in the Republic of Croatia. In the first chapter, a short introduction to the given topic will be made. The subject and goal of the work will be explained, followed by the sources and methods of collecting relevant data, the content and structure of the work itself. The next chapter contains characteristics of small and medium enterprises. The conceptual definition of small and medium-sized enterprises, their role in the economy and the institutional framework for their operations are explained. In the third chapter, the COVID-19 pandemic and its implications for small and medium-sized enterprises in the European Union are described in more detail. Furthermore, policy responses to the crisis caused by the COVID-19 pandemic in the European Union are explained and an overview of existing research on the effects of the pandemic on small and medium-sized enterprises is given. The next chapter focuses on the effect of the COVID-19 pandemic on small and medium-sized enterprises in the Republic of Croatia. Thus, the development and importance of small and medium-sized enterprises in the Republic of Croatia in the pre-pandemic period is described, small and medium-sized enterprises are analyzed in the pandemic period, and the support for small and medium-sized enterprises during the pandemic is reviewed. In the fifth and last chapter of the work, a conclusion is drawn on the topic.