In recent decades, there has been an expansion in transnational mergers as well a continuous increase in the number of national merger control systems, which has resulted in the multiplication of jurisdictions, called to act over cross-border mergers. Merger plans must be notified to different competition monitoring authorities before they can be executed. This creates a major international issue as a merger may be subjected to a plurality of national analyses that may result in contradictory or inconsistent decisions. This paper describes this issue and analyses some recent cross-border mergers. It then offers arguments for a debate about possible solutions. JEL codes: K21, K33, F23, F53