This article investigates the effect of social ties between acquirers and targets on merger performance. We find that the extent of cross-firm social connection between directors and senior executives at the acquiring and the target firms has a significantly negative effect on the abnormal returns to the acquirer and to the combined entity upon merger announcement. Moreover, acquirer-target social ties significantly increase the likelihood that the target firm׳s chief executive officer (CEO) and a larger fraction of the target firm׳s pre-acquisition board of directors remain on the board of the combined firm after the merger. In addition, we find that acquirer CEOs are more likely to receive bonuses and are more richly compensated for completing mergers with targets that are highly connected to the acquiring firms, that acquisitions are more likely to take place between two firms that are well connected to each other through social ties, and that such acquisitions are more likely to subsequently be divested for performance-related reasons. Taken together, our results suggest that social ties between the acquirer and the target lead to poorer decision making and lower value creation for shareholders overall.