Purpose – This paper aims to elaborate and discuss key Islamic principles of relevance to environmental ethics and sustainability agendas and reflect on implications for the operations of Islamic financial institutions (IFIs). Design/methodology/approach – An exploration of the tenets of environmental sustainability enshrined in Islamic Shariah through a review of key Islamic texts and relevant prior literature. Findings – The Islamic approach to the environment is holistic and unequivocal. Qur’anic verses describing nature and natural phenomena outnumber verses dealing with commandments and sacraments. Centrality of the environment in the Shari’ah and the Islamic injunction to command right and forbid wrong are suggestive of an affirmative sustainability agenda for IFIs. Practical implications – Implications and opportunities for corporate managers, environmental movements and policy makers. Originality/value – By encouraging Muslim engagement in Ijtihad, this work contributes to conceptual development within Islam. It will also be of value to accountability and ecology researchers seeking a better understanding of ecological practices and the internal histories of religions.