The aim of the paper is to assess disparities in social development of rural areas in Poland in the context of sustainable development. Social development is a multidimensional process; therefore, it requires a two-stage research procedure. The first stage consists in the analysis of the regional differentiation of the indicators for social development of rural areas in Poland in the context of implementing the concept of sustainable development, which is further divided into five social components. The second stage is a multidimensional assessment of disparities in social development of rural areas in Poland, carried out using a taxonomic measure of development. This measure enabled both classifying voivodeships in terms of the achieved level of social development of rural areas and identifying voivodeships with similar characteristics. The time scope of the analysis covered 2008 and 2018 , while the territorial scope covered 16 Polish voivodeships. The study has found a large regional differentiation in terms of social development of rural areas, which confirms the thesis on regional polarization discussed in the literature. It turns out that none of the regions can be regarded as a model example of social development. The results indicate the need for taking measures to reduce development disparities at the social level in rural areas between better and less developed voivodeships. This is necessary to counteract the exclusion of underdeveloped regions.