Despite recognition of the importance of sustainable development and its related movements: fair trade, responsible consumption and food sovereignty, interest in its analysis and research is relatively recent among Latin American scholars. While there is palpable growing interest in these issues, there is a big gap in explaining the inclination of college students belonging to the Millennials to adopt ethical behaviors consistent with the sustainable development movements. This exploratory study aims to contribute to the understanding of this phenomenon, exploring the effect of bioethical principles in the evaluation and intention of ethical behavior that are consistent with sustainable development. The authors propose a model of decision-making that adapts, integrates, and renews various components of the model, the bioethical principles proposed by Beauchamp and Childress (2001) and the Transtheoretical Stages of Change Model of Prochaska and DiClemente (1984). This study contributes to research ethics from a theoretical perspective and practical standpoint.