The research area of this chapter includes determinants that influence early-stage entrepreneurial activity in the agro sector in the countries of the Southeast Europe region (SEE). The research implies determinants such as national culture, individual entrepreneurial characteristics, as well as entrepreneurial aspirations (growth, innovation, and internationalization). Data for the research was provided by the Global Entrepreneurship Monitor database. To form a research sample, data were collected from agrobusiness entrepreneurs in Hungary, Slovenia, Romania, Croatia, Bosnia, Herzegovina, and North Macedonia. In line with the theory, past research and the result of empirical research, authors propose a model consisted of determinants that influence early-stage entrepreneurial activity in the agro sector in the countries of SEE.