Transnational humanitarian relief by non-governmental organizations (NGOs) can have harmful – sometimes even disastrous – unintended effects. Transnational NGOs respond to these negative unintended consequences of humanitarian aid in a variety of ways, including providing aid illicitly, and retracting aid. These responses, important in their own right, address a question that political theorists and philosophers have thus far virtually ignored: what is the nature and character of obligation in the context of benevolence? In other words, what do those who engage in benevolent acts owe to those affected directly or indirectly by such acts, and why? The proposed dissertation seeks to explore this question, by examining how to exemplary NGOs – Medecins Sans Frontieres and the International Committee of the Red Cross – respond to the negative unintended consequences of humanitarian aid. I look first at the specific reasons, considerations, and judgments that inform NGOs’ decisions about how to deal with the negative unintended consequences of aid, and then ask – in a more abstract and philosophical vein – what NGOs’ language and practices reveal about their conceptions of their obligations to humanitarian aid recipients and others affected by the provision of humanitarian aid.