The growing emphasis on sustainable and responsible business conduct has positioned Environmental, Social, and Governance (ESG) practices as a central determinant of corporate strategy and long-term value creation. This study examines the impact of ESG practices on the financial performance of selected companies, with a particular focus on both market-based and accounting-based performance indicators. Using ESG performance scores as a proxy for sustainability practices, the research analyses how contemporaneous and lagged ESG initiatives influence firm performance. The study adopts a quantitative research design supported by established theoretical frameworks, including stakeholder theory and signalling theory. The findings suggest that ESG practices exert a positive influence on financial performance, with stronger effects observed in the current period compared to lagged ESG initiatives. The results highlight the importance of continuous and dynamic ESG integration rather than reliance on past sustainability efforts. The study contributes to the growing literature on ESG by offering fresh insights into the timing and relevance of ESG practices for corporate financial outcomes and provides practical implications for managers, investors, and policymakers.