This paper examines the effects of fund portfolio similarity on performance and flow in Korean equity fund market. In the period of 2001 ~ 2018, average portfolio overlaps of Korean domestic equity funds is 44%, meaning that about half of a given fund’s portfolio is same with other funds in the industry. Moreover, average investment weight on top 10 popular stocks is 44% and top 30 is 67% meaning that portfolio similarity in Korean equity fund market is quite high. Although, performance of frequently overlapped stocks show positive and significant 4-factor adjusted alpha, funds with higher portfolio overlap and higher weights on frequently overlapped stocks do not significantly outperform low overlap/low weights on frequently overlapped stocks funds. Lastly, these funds experience significant and negative money inflow, indicating that Korean fund investors prefer funds with more unique investment strategy.