Group awareness is an emerging topic in research on computer-supported collaborative learning (CSCL). It covers the knowledge and perception of behavioral, cognitive, and social context information on a group or its members. A central aim of CSCL-related research on group awareness is the development of tools that implicitly guide learners’ behavior, communication, and reflection by the presentation of information on a learning partner or a group. This special issue comprises six empirical contributions and a concluding discussion that present a broad spectrum of current research on this topic including behavioral, cognitive and social group awareness. An introductory outline of how group awareness is formed, processed and translated in action along the contributions is intended to integrate the diverse research activities on group awareness in CSCL environments.