The debate on optimization of policies and instruments of the European agriculture has been lasting for several decades and still there is no unified opinion on that aspect. Although there is an unanimity on targets these policies should achieve, there is an ongoing discussion on policy tools and instruments for practical implementation of CAP in connection with agri-environmental payments. The aim of this paper is to contribute to this discussion by looking at the developed approaches to evaluate environmental and economic efficiency simultaneously as well as to examine possibilities for more targeted agricultural support by an implementation of economic-environmental efficiency analysis. In this regard it is especially interesting to consider the case of support for sustainable land use practices such as in HNV farming (high nature value) and the opportunities of implementing such analyses in areas of HNV agriculture: we consider in particular disadvantageous mountain areas in the Romanian Carpathians and the bordering areas in the Ukrainian Carpathians.