Studying identity, be it ethnic, cultural, linguistic, national or regional, in the contemporary context becomes troublesome because the scholar is faced with a whole range of social and cultural forms that co-exist uncomfortably with existing definitions of social identity. Moreover, although identity has been a central concern in a number of disciplines during the past decades, there has been considerable disagreement regarding the methodological tools most suitable to study its formation and change. The aim of this Special Issue is to discuss the usefulness of the very concept as well as the main methodological tools suitable to analyse identity-related phenomena today. In this introductory chapter, we provide for a general definition of the concept and elaborate on recent theoretical and conceptual developments regarding the nature of identity in the sociological, discourse studies and social psychological literature. In the concluding section, we introduce the individual contributions presented in this issue.