The topic of this thesis is the Analysis of the possibility of expanding the business of Sisak auto d.o.o. on the market of the Zagreb County. The aim of the research was to determine which internal and external factors would affect the company Sisak auto d.o.o. when entering the Zagreb County market. It was determined that in all aspects, talking about the long-term business of the company, the positive balance, but also the reputation in the market of Sisak - Moslavina County, the company Sisak auto d.o.o. has the prerequisites to enter a new market, as well as a larger market such as Zagreb County. The theoretical part of the entry to the Zagreb market had to be substantiated by empirical research. The respondents expressed their satisfaction with the current situation on the Zagreb County market. The company Sisak auto d.o.o. using survey results can identify market entry opportunities, but also turn the shortcomings of competitors into an opportunity for better market positioning. In today's time of globalization, sudden changes, but also strong competition, it is necessary for a company to develop and grow in the market. Sisak auto d.o.o. according to the life cycle it is entering the third phase and at this point it is necessary to introduce changes in the business. The theoretical and empirical part of the paper confirmed how the company can expand part of its business to the Zagreb market in certain changes that the new and larger market requires. Using strategic tools such as SWOT and TOWS analysis, Ansoff matrix, Porter's model, the company will see its own advantages and disadvantages and analyze the target market.