The article presents the concept of sustainable development of socio-cultural capital with particular emphasis of the role of cultural institutions as factors influencing their development in a human being. In the article, the concept of social capital and cultural capital have been treated as complementary to each other, which is why they have been identified as a socio-cultural capital. Sustainable development of this capital in many cities of the world meets a number of problems reflected in the quality of life of its residents. In this article, a part of the town is analyzed which, due to political decisions made at the end of the First World War, has been divided for a hundred years into Cieszyn on the Polish side of the border and Czech Cieszyn (Český Těšín). This area is an example of how historical, political, demographic and educational conditions form the basis for the quality of socio-cultural capital. It is also an example of cooperative activities between local government institutions and third sector organizations. Despite many differences between the residents of Cieszyn and Czech Cieszyn, the conducted analysis points to the formation of a socio-cultural capital of a combining character, according to how Robert Putnam wrote about such phenomena, without neglecting the diversity of goals and interaction groups.