The aim of this dissertation is the identification, description, and explanation of the process through which cultural, psychological, social, political, and administrative factors that are present in a foreign acquirer interact with the Brazilian acquired company, affecting its organizational knowledge. The latest ten years have witnessed the growing debate on globalization and its impacts over the world society, nations, organizations, and individuals. The weakening of the power of the national State, chiefly as an economic agent, and the intensification of worldwide business competitiveness have been accompanied by waves of mergers and acquisitions that have affected countries, as Brazil, eager for foreign direct investment in several industries, such as the financial sector. Although some strategic thought schools, as the resource-based approach, reckon the importance of organizational knowledge - mainly in its tacit dimension - as a sustainable competitive advantage, it has been examined in a fragmented way, separated from organizational learning and change, to which processes it is inextricably linked. Furthermore, the process of knowing appears isolated from its context, although several factors need to be considered, mainly when it is necessary to study their manifestations in companies acquired by foreign organizations. This study focuses on the retail areas of two banks that have been bought by foreign - a British and a Dutch - banks. The methodology used was a two-case study, under a qualitative approach, based on semistructured interviews with branch managerial personnel of the two banks, in Rio de Janeiro. Evidences brought about by these interviews have been triangulated with those coming from the perusal of public documents about both the foreign owners and the Brazilian acquired banks; from the archival records to which we are allowed to have access; from the direct observation of some cultural artifacts in the retail branches; and from some brief interviews with qualified informants in the corporate headquarters of the Brazilian acquired banks. The resulting analysis shows the insufficiency of current theoretical models from several isolated perspectives - such as knowledge management; organizational knowledge; knowledge organizations; organizational change; national cultures; organizational culture; internationalization process - to grasp the complexity of organizational knowledge phenomenon and suggests an integrative approach rooted in cognitive biology and social constructionism.