This study examines the market reactions by investors of Korean agribusiness companies following five foot‐and‐mouth disease (FMD) outbreaks using an event study analysis. The results suggest that the FMD outbreaks caused the stock market to react in both a negative and positive manner to allied companies. The results also suggest that the market reactions were more gradual than instantaneous to the FMD outbreaks. Furthermore, the FMD outbreaks appear to have increased the volatility of the daily returns with the smaller companies facing the largest changes in volatility.