The article presents new data on income distribution in Korea from 1976 to 2010. The researchers used income tax records and national accounts to estimate top income shares. They found that income concentration was low and stable until the 1990s, but increased rapidly after the 1997 financial crisis. Higher income groups gained more share during this period. Compared to other countries, Korea's income concentration was low, similar to Europe and Japan, but approaching levels seen in English-speaking countries. Household survey data may underestimate actual income inequality in Korea.