This study intends to explain how a firm competitively reacts to its rival's executive turnover. From an awareness-motivation-capability perspective, I contend that a firm's executive turnover impairs its capacity for competitive responses, owing to the temporary instability in coordination among its executives. Accordingly, since its rival's executive turnover is recognized as an opportunity to attack, a focal firm would engage in competitive actions against its rival more frequently when it experiences greater executive turnover. This relationship is strengthened by the non-routineness of the selection of the rival's incoming executives, but is weakened by the focal firm's market share relative to the rival. Empirical tests using a sample of the leaders and challengers of 13 duopolistic industries in Japan from 1997 through 2006 lend support to the hypothesized relationships.