Marketing mix represents one of the most important and well-known terms in marketing. The goal of this final paper is to get to know the core of this subject's theory, see the functioning and efficiency of GPP Osijek's operations on a concrete example, and find out if there are differences between theory and reality. When writing this final paper, the historical research method and the test method were used. Both secondary and primary data were used. The marketing mix represents the coordinated action of four elements: product, price, distribution, and promotion. In the paper, the economic entity's products/services, the process of formation of their prices, and the influence of these prices on the market were investigated. The research part of the work also shows distribution and sales as an element of the marketing mix of GPP Osijek and shows their promotional activities and their results on examples of implemented campaigns. A comparison of the functioning of the marketing mix in theory and an example showed that the business entity GPP Osijek also used theoretical knowledge when creating the marketing mix. Modern times present new challenges to business entities, and it is necessary to respond to them in a timely manner. Harmonization of all elements of the marketing mix is the key to a successful business in today's time, so harmonizing the elements and creating a strong marketing mix is the task of every business entity