Literature has advanced two contrasting theoretical perspectives related to the governance structure of business groups: the ‘value-constraining’ perspective, which focuses on principal–principal agency conflict and organizational inertia theory, and the ‘value-enabling’ perspective, which emphasizes the role of business groups in mitigation of institutional voids. Building on these two competing lenses, we develop hypotheses to examine post-acquisition performance of affiliate firms relative to stand-alone firms. As our empirical context, we study 440 majority-stake, domestic and cross-border merger and acquisition deals closed by Indian firms during the period 2002–2013. The results imply that in emerging markets, despite concerns of organizational inertia and principal–principal agency issues, the value-enabling impact of group affiliation persists. We also examine the contextual impact of intergroup heterogeneity owing to group diversification on post-acquisition performance and find that greater group diversification leads to better performance for affiliate acquirers.