This chapter reviews the origins, approaches and roles associated with the use of cultural historical activity theory (CHAT) in information systems (IS) research. The literature is reviewed and examples are discussed from IS and related fields of human-computer interaction (HCI), computer supported cooperative work (CSCW) and computer supported collaborative learning (CSCL), to illustrate the power of CHAT in IS research as well as its link to appropriate research methods. After explicating the value of its use, the chapter concludes by discussing theoretical and methodological implications of applications of CHAT in examining real-world problems in IS research.