The aim of this article is to assess the impact of social capital on socio-economic development of rural communities in the Warmia and Mazury Province. In the course of the study two synthetic indicators were calculated with the use of the TOPSIS method. One characterised social capital, the other the level of socio-economic development. The data used to determine the indicators (characterizing social capital and socio-economic development) were obtained from the Local Data Bank of the Central Statistical Offi ce and the National Electoral Commission for 67 rural communities from the Warmińsko-mazurskie voivodeship. Subsequently, linear ordering of the examined units was conducted and typological classes (I–IV) were determined, characterising the level of both analysed indicators. It was established that rural communities in the Warmińsko-mazurskie voivodeship do not show a large variation in terms of socio-economic development and social capital. Then, the relation between social capital and the level of socio-economic development was studied. As shown by statistical analysis, there is a positive, but low statistical dependence between the level of social capital and the level of socio-economic development. In turn, in the case of commune division into typological classes, compatibility was found between the discussed indicators, but only for 26 units, which constitutes only 40% of the analysed communes.