In the focus of this graduate thesis, the issue of brand influence on purchasing decisions has been considered. Making purchasing decisions is a systematic approach based on the following phases: identifying problems, searching for information, evaluating alternatives, buying decisions as well as post-paid activities. The decision-making process is largely determined by internal influencing factors as well as external influencing factors that shape consumer behavior. A brand or brand is one of the elements of a product that can potentially affect the decision making on purchasing a product / service. The mark represents everything that is seen, heard, read, knows, feels or thinks about a particular product, business entity or the service it provides. The brand's significance in modern business conditions is manifested in: simplified handling of products and services by modern business entities, organizing and managing inventory and accounting, providing legal protection, displaying product/service quality and providing competitive advantage. Consequently, the subject of this graduate thesis is the determination of the influence of the mark on decision-making. The objectives of the work are to: mark the importance of the brand of products, to determine the influence of the product brand on making a decision about the purchase of products and to expand the existing knowledge of branded issues. The following methods were used in the design of this graduate thesis: method of analysis, synthesis method, inductive method, deductive method and generalization method.