ŠTEFANOVIE, Patrícia: Marketing mix of the companies O2 and Orange. [Diploma thesis]. Zvolen: Technical University in Zvolen. Department of Marketing, Trade and World Forestry. Consultant: Ing. Miroslava Triznová, PhD. Qualification level: Master. Zvolen:TUZVO, 2017. 62 pages. The aim of this diploma thesis is to find out how customers perceive the marketing mix of companies providing telecommunications services and then based on the results of our research, provide suggestions how to improve the marketing mix. The aim is to point out the importance of customers in a competitive service environment. The main subjects of our research are companies Orange Slovakia, a.s. and O2 Slovakia, s.r.o. The theoretical part of the thesis is focused on laying the theoretical groundwork for our thesis–we clarify the definitions of services, marketing mix, and their interconnection into the marketing mix of services. After we describe the tools of marketing mix in more detail we set the goal and methodology of the thesis. The analytical part of our thesis is devoted to analyzing the marketing mix of the two companies O2 and Orange. Subsequently, we process the results of the questionnaire survey of the customers of these companies. At last we focus on suggestions for improvement of individual marketing mixes.7Key words: companies providing telecommunications services, marketing mix of services, customer, questionnaire survey