This paper explains the strategic penetration through mergers and acquisitions in international financial large corporate in emerging countries like Mexico and the clash of European and Mexican management cultures. As a case study is taken as a basis, the merger and consolidation of the Spanish Banco Santander in Mexico, what was your strategy for fusion of Mexican banks? How was his way of governance in the country? Concluding and Banco Santander through mergers and acquisitions have become the fourth strongest banking Mexico and one of the strongest banks in the world, as part of the explanation is considered their form of governance.