The mixed crop and livestock farming represents significant share in agricultural output in the Czech Republic. So, it raises questions about determinants of its production efficiency. The aim of the article is to evaluate production efficiency and its determinants of mixed crop and livestock farming among the EU regions. The DEA method with variable returns to scale (DEAVRS) reveals efficient and inefficient regions including the scale efficiency. In the next step, the two-sample t-test determines differences of economic and structural indicators between efficient and inefficient regions. The research reveals that substitution of labor by capital/ contract work positively affects income indicator Farm Net Value Added per AWU. The significant economic determinants of production efficiency in mixed type of farming are crop output per hectare, livestock output per livestock unit, productivity of energy and capital. Agricultural enterprises in inefficient regions have more extensive structure and produce more non-commodity output (public goods).