The globalization of trade has made it necessary to establish an international network of competition laws. Accordingly, more than a hundred jurisdictions have now introduced some kind of competition law provisions into their national legislation. However, it is notorious that enforcement in many countries is weak, erratic, hampered, or sometimes even nonexistent. This comparative study sheds clear light on how competition law provisions are enforced (or are supposed to be enforced) in over ninety jurisdictions worldwide, providing valuable knowledge about both the obstacles that competition authorities face and the characteristics that seem to determine the success of certain competition law systems.