International mergers and acquisitions (M&As) have been increasingly used by emerging market enterprises (EMEs) as a springboard for strategic assets to overcome latecomer disadvantages and build sustainable competitive advantages. While current literature only focuses on the M&As’ impacts on acquirers, little is known about the impacts of EMEs’ international M&As on their external stakeholders, such as rival firms. Based on the longitudinal data covering 325 large international M&As completed by Chinese public manufacturing firms during 2009–2015, empirical results show that international M&As at the industry level have significant negative influence on the sustainable performance of acquirers’ rivals, and these negative relationship will be accentuated when the international M&As are horizontal M&As, when rivals are carrying out cost leadership strategy, and when those M&As are completed in the high-tech industry. This study enriches the literature of international M&As and the economic pillar of sustainability by pushing current research toward rival’s perspective and denotes that firms need to consider the potential negative impact on the sustainability of their outside stakeholders (e.g., other firms and whole industry). It also generates practical implications for firms to actively deal with potential negative effects of competitors’ international M&As on their sustainable performance, especially those players in the high-tech industry.