The article focuses to the spatial dimension of sustainable development. Social equity and justice is one of the fundamental features of sustainable development. Marginal regions, i.e. areas set for some reasons out of the main developmental trends, seem to be very good examples of social inequity from the spatial point of view. Therefore, the existence and extent of the marginal regions may serve as one of spatial indicators describing sustainability of development in individual states. In this context there appears one important question - what criteria should be used to delineate these areas. The article can be seen as a proposal of indicators to identify marginal regions within the Czech Republic. The proposal itself has been inspired by the regional policy of the European Union, taking, however, into account the practical issues of statistical data availability. We suppose that the proposed indicators may become useful for the purposes of national statistics, in decision making of the Ministry for Regional Development as well as in the process of harmonization of the Czech Republic regional policy with the European milieu.