Every economic sector, every single industry, every economy, and even every firm has its specific financial structure. Given that it is not possible to examine thousands of individual companies for scientific purposes, it is necessary to at least examine the differences between individual sectors, industries and countries. At the same time, the formation and optimization of the financial structure is influenced by a myriad of diverse factors that financial managers should take into account in their decisions. Thanks to these facts, more and more researches had been created for over half a century. This research expands knowledge in seven selected countries of Central and Eastern Europe – the Visegrád Group, Bulgaria, Slovenia and Romania. The aim of the research is to evaluate, based on the Generalized Method of Moments, the relationship between the six selected factors and the indebtedness level in companies belonging to the agricultural, forestry and fishing industry. The subject of the research is medium, large and very large companies during the years 2009 to 2016. The research deals with the influence of profitability, liquidity, asset structure, economic development, inflation and interest rates on the total, long-term and short-term indebtedness of companies. The main finding of the research is that companies are influenced by both internal and external determinants. However, even though the industry should be neutral, external determinants – GDP growth rates, inflation rates and interest rates – have a more significant impact on the debt level. The results of this research will not only extend current knowledge in the field of corporate finance, but at the same time, the results may be stimulating in setting support rules for public administration and even European institutions, as the selected industry is strongly linked to subsidy policies.