The chapter examines in depth the connections between ESG factors and the main economic and financial variables of the company. The impact of ESG performance on key elements such as profitability, creditworthiness, cost of capital (both debt and equity), company valuation and capital structure is analysed. The text delves into how the integration of ESG criteria contributes to reducing uncertainty perceived by investors, improving access to credit and containing operational and reputational risk. Particular attention is paid to the link between ESG and cost of capital, concerning both the mitigation of perceived risk and the information transparency deriving from sustainable reporting. The chapter highlights, through comparison with the most recent literature, how companies with high ESG scores tend to show greater financial stability, better long-term performance and a competitive advantage in capital markets. The discussion aims to go beyond a merely descriptive approach, laying the foundations for a theoretical-financial modelling of the value generated by ESG investments. A coherent picture emerges in which sustainability and corporate finance are not opposed, but rather integrated into an evolutionary vision of value creation.