Extreme diff erences in agricultural holding size, existing not only among the countries within the EU as a whole but also within the farm structures of the individual countries, create a considerable uncertainty for establishing the optimal political and economic instruments to support sustainable rural development. Th e study explores the determinants infl uencing the spatial volatility of agricultural holding size at both the EU scale and the national scale of the Czech Republic, the latter of which has the largest mean agricultural holding size in the EU. While some factors are identical for both the EU and the Czech Republic, other eff ects can only be evaluated at the European or international scale, and still others can be evaluated only at the national scale. Th e only factor found in this study to be signifi cantly associated with the agricultural holding size on the European scale was the wheat production. On the Czech national scale, land consolidation, unemployment rate, and soil fertility were signifi cantly associated with the agricultural holding size. Th e study found that in the Czech Republic, the number of farms was increasing, while at the same time the agricultural holding sizes were decreasing. Th is is an opposite trend in comparison to the EU as a whole, where the number of farms is diminishing and the sizes increasing.