Owing to the country’s heavy reliance on exports, the role of foreign exchange intervention in South Korea’s economic development is self-evident. The effectiveness of the intervention is what we are concerned with in this paper. Recently, a growing body of literature has engaged in exploring the asymmetric effects of foreign exchange intervention both theoretically and empirically. Against this background, we employ a threshold vector autoregression (TVAR) model in parallel with its generalized impulse response functions (GIRFs) to show that there are asymmetric effects of the Bank of Korea (BOK)-led interventions regardless of the volatility regimes.