This paper aims to estimate regional economic impacts of Gaesung Industrial Estate by using multiregional input-output model. For doing so, this study divides regional economic impacts into three types of effects: 1) exports from South Korea to Gaesung, 2) household consumption due to wage and salary of South Korean workers working in Gaesung, and 3) investment due to corporate profit of South Korean firms operating in Gaesung. The findings from the analysis can be summarized as follows: First, about 90% of total economic impacts of Gaesung Industrial Estate is generated by exports to Gaesung, which include construction and production facilities, and intermediate goods for production in Gaesung. Second, about 2/3 of total economic impacts generated in South Korea takes place in the Seoul Metropolitan Area (SMA), indicating the SMA is the biggest economic beneficiary of Gaesung Project. This finding suggests that the SMA will play a crucial role in the development of South-West region of North Korea including Gaesung and Pyungyang after reunification, and policy-makers need to pay attention to the development of northern part of the SMA, which will be an outpost of economic development of North Korea