Sustainable decision-making, which involves choosing alternatives that meet present needs without compromising the future, has gained significant importance in light of the increasing social and environmental concerns. This study introduces a novel framework that defines ethical sustainability in decision-making as making ethically sound and future-oriented choices grounded in realism and impartiality. These two key principles ensure that decisions are based on consideration of actual consequences and fair treatment of all affected stakeholders. The study's unique contribution lies in identifying four distinct decision-making styles: tactical altruism, emotional altruism, egoism, and ethical sustainability. While each style might appear ethical, the study argues that only decisions rooted in realism and impartiality can be considered sustainable. The study also presents a newly developed and validated measurement instrument to assess ethical sustainability in organizational decision-making, using survey data from 100 managers across sectors. The findings demonstrate satisfactory reliability and validity, revealing meaningful links between motivational drivers (intrinsic, extrinsic, and prosocial) and decision-making styles and their influence on organizational trust. As an exploratory study, this paper offers a unique framework for understanding the moral underpinnings of sustainable decision-making and lays the groundwork for future research and practical applications. We hope this contributes meaningfully to ongoing research in ethical leadership, corporate sustainability, and values-based organizational behavior.