In this study, we examine how the effects of mergers and acquisitions on organizational performance are moderated by human resource management (HRM) centrality. We differentiate three types of ownership change: mergers, bidder, and target acquisitions. The study i anchored on the literatures addressing strategic human resource management and strategic contingencies of intra-organizational power. In an analysis of the data from the 2005 Cranet survey, results showed that (i) formalization attenuated a positive impact of bidder acquisitions and aggravated a negative impact of mergers on performance, but (ii) HRM strategic involvement and centralization of HRM practices boosted a positive impact of bidder acquisitions on performance. The study offers new insights about the role of HRM centrality, and suggests that mergers and acquisitions should be studied as differentiated ownership change processes.