Abstract. This paper proposes an evolutionary model of business groups in emerging economies by tracing the evolution and restructuring of business groups in Korea. Underlying our model are two theoretical premises: (1) the value-creation potential of business group diversification depends on the quality of the economic institutions supporting the economy; and (2) the strategy-structure fit is a key determinant of diversified business groups' performance. Combining these two premises, we link business group evolution with institutional context, sources of competitive advantages, diversification strategy, and structure. To illustrate our theoretical arguments, we provide an overview of the evolution of chaebols in Korea and examine the restructuring of two major business groups, LG and Hyundai Motor. We conclude by discussing implications for management, public policy, and future research.