Purpose - The purpose of this paper is to expand the field of sustainability/corporate social responsibility research to include a focus on leadership. It aims to present an exploratory study of senior leaders in organizations formally adopting principles of sustainability and how these leaders enact the tasks of leadership: setting direction, creating alignment, and maintaining commitment within the context of sustainability. Design/methodology/approach - The study uses a qualitative approach, sampling senior executives from organizations formally adopting sustainability practices and using a structured interview to uncover their leadership practices related to sustainability. Findings - Leaders adopting sustainability practices are similar to other "effective'' leaders and yet they also have additional capacity and mindset to include a wider expanse of stakeholders and a different mindset as to the purpose of organizations. Research limitations/implications - Limited sample of senior executives/CEOs, as well as a difficulty in attesting an organization's level of commitment to sustainability; this research links the field of leadership to the field of sustainability and calls for a more in-depth investigation into the roles leaders and leadership play in the successful implementation of sustainability practices. Originality/value - Leaders interested in pursuing a sustainability agenda should pay attention to how the concept is framed and introduced into the organization; they should build capacity in their systems (educational, communication, rewards, performance, etc.) and culture to support sustainability, and broad and deep stakeholders engagement is essential for success.