Sociocultural theory is increasingly popular as a paradigm for research in education. A recent member in this family of theories is introduced--cultural-historical activity theory (CHAT)--that shows much promise to complement and invigorate the field of educational change, a large, multi-faceted, and persistent problematic. In particular, CHAT-based research can address five areas where educational change research experiences weaknesses and shortcomings: (1) the failure to fully analyse the context; (2) a tendency towards reductionism rather than embracing complexity; (3) low sensitivity to the effects of power and politics; (4) lack of concern with emotions and identity; and (5) the rapidity at which new innovations are often introduced. These arguments are exemplified with a case study of a secondary school in Singapore that had devised a new inquiry-based science curriculum. The paper concludes with some implications for promoting CHAT-based research in educational change. (Contains 23 notes, 1 table, and 1 figure.)