The aim of the thesis is to define and evaluate the marketing mix of the fitness centre World Gym Fitness Group Inc. and to recommend changes that would increase the efficiency of the marketing mix. The theoretical part is divided into two chapters and focuses on marketing mix of services and marketing environment. Within the crucial practical part there has been run a research to determine the mission of the company and clients´ satisfaction. The research is based on direct observation. The practical part contains at first general characteristics of the World Gym company. The next chapters are focused on the individual parts of the marketing mix of the fitness centre. The marketing mix includes services, price, promotion, distribution, physical environment and people. At the end all findings are summarized in the SWOT analysis and recommendations are designed to increase the efficiency of the marketing mix of the fitness centre.