In order to achieve a sustainable growth and to respond to social pressures, firms develop their Corporate Social Responsibility (CSR) policy. Corporate Governance, especially the board of directors, plays here a strategic role by integrating the environmental, social and societal objectives in the decision-making process. Based on the French case, this dissertation analyzes how corporate governance may foster CSR inside firms. First, I demonstrate that CSR motivation is an important trigger of CSR awareness. Second, I study how the composition of board of directors theoretically affects firm outcomes. Third, I evaluate three CSR demands from shareholders, stakeholder and society in terms of board composition (independence, stakeholder representation and gender diversity inside the boardroom) and their impact on firm performances. I conclude with some recommendations in terms of public policy and regulation to foster sustainable development through firms.