Corporate social responsibility is a very prominent subject nowadays. For companies, investing in socially responsible actions has become essential since this kind of investment can result in a better corporate image, competitive advantage and financial returns. Moreover it legitimates the organization. The concept of corporate social responsibility includes the organization s relationship with its stakeholders and the action occurs in several areas, being the social area the one that stands out in Brazil. The purpose of this dissertation is to understand how has been occurring the corporate social responsibility institutionalization in the pharmaceutical companies and the impacts and consequences of this process to the communities reached by the social projects undertaken by those companies. A literature review about corporate social responsibility, stakeholder theory and institutional theory was conducted along with a qualitative and exploratory research. Documentary research was conducted and interviews, questionnaires and case studies were prepared about four pharmaceutical companies. The collected data were submitted to content analysis and subsequent triangulation. The results suggest that corporate social responsibility in considered pharmaceutical companies is moving to a stage of full institutionalization with some features of the institutional stage. Besides, the evolution of corporate social responsibility and its institutionalization in these companies have shown positive impacts on communities due to well-structured social actions performed. The results are satisfactory and different from simple philanthropy.