Since the early 1990s, effects of testing on teaching and learning have drawn increased attention. However, most studies in second language assessment have been quantitative.BRAlthough a few studies were qualitative, they lacked a conceptual or theoretical framework, thus failing to provide a comprehensive picture of washback. This is also true in the Korean context. An operational model is needed to effectively investigate washback. This paper reviews prior research studies that have introduced seminal washback hypotheses and empirically driven operational models. These studies have identified significant macro- and micro factors such as curriculum, perception, beliefs, students’ and teachers’ previous experiences, and tests that can impact teaching and learning. Based on a review of existing operational models, this paper proposes Engeström’s activity theory as a new and comprehensive model of washback that can be adopted in any context to analyze high-stake language examinations. These findings have theoretical and practical implications for qualitative washback research.