In our introductory article, we outline the main sociolinguistic features of Russian as a heritage language of post-Soviet immigrants in European settings and beyond. We offer a general overview of the evolution of Russian as a global language, with a particular focus on its geodemographics and economic and social value as a lingua franca . Based on this, we analyse the main principles defining the maintenance of Russian as a language of migration and as a heritage language in different countries, and emphasise the most important questions that still need to be addressed in this field of research. The main objective of this special issue is to combine the most recent research on the vitality of different languages of post-Soviet republics in new political milieu, with a particular focus on European and Asian countries, but there are other objectives as well. We propose to explore the factors that have either favoured or hindered the maintenance and transmission of languages of post-Soviet immigrants and repatriates, and how these sociolinguistic processes become evident in language vitality on both private and public levels. Our special issue primarily addresses the questions of family language policy, new language contacts and their management, and linguistic landscape in heritage speakers, diasporas and their new settings in Europe, Asia and the US.