Th e main aim of the article is recognition of the issues of complexity in economics with the particular emphasis on agriculture, as well as indication of resulting implications for this sector. Complexity in economic theory is in general perceived from the perspective of external eff ects, while the problem may also have other connotations: as the so-called fallacy of composition, or the phenomenon of entropy. Th e problem of complexity indicates the need for further refl ection on the holistic perception of economic processes. Th is is particularly evident in the ca se of agriculture, when the evaluation based mainly on microeconomic approach from the perspective of the eff ect/cost relationship loses sight of the environmental, social, and cultural context. Focus should also be put on the entropy approach, which takes into account the openness of socio-economic systems and the limitations of resources, including the environment. Both the operating practice of agriculture together with the institutional surrounding, and agricultural economics are more advanced in the area of solving the problems of complexity on the practical and theoretical grounds, but there are still many issues that require solutions, particularly quantifi cation of externalities. Th e work is theoretical in nature and a heuristic approach was applied in the considerations.