With the increasing frequency and severity of disasters and the increasing number of patients living with kidney disease, on dialysis and with transplants around the world, the need for kidney care in humanitarian settings is increasing. Almost all humanitarian emergencies pose a threat to kidney health because all treatments are highly susceptible to interruption, and interruption can be deadly. Providing support for people requiring dialysis in humanitarian settings can be complex and is associated with many trade-offs. The global kidney care community must become familiar with the ethics, principles and duties essential to meeting the overarching goals of ethical and effective disaster relief. Ethics principles and values must be considered on the individual, public health and global levels. The wellbeing of a single patient must be considered in the context of the competing needs of many others, and optimal treatment may not be possible due to resource constraints. Public health ethics principles, including considerations of triage and resource allocation, maximization of benefit and feasibility, often become directly relevant at the bedside. Individuals delivering humanitarian relief must be well trained, competent, respectful and professional, while involved organizations need to uphold the highest professional and ethical standards. There may be dissonance between ethical guidance and practical realities in humanitarian settings, which for inexperienced individuals may present significant challenges. Sustaining dialysis care in emergencies brings these issues starkly to the fore. Preparedness for dialysis in emergencies is an ethical imperative that mandates multisectoral stakeholder engagement and action, development of surge response plans, clinical and ethics guidance, and transparent priority setting. This manuscript outlines common ethics challenges and considerations that apply in all humanitarian actions, and illustrates their relevance to kidney care as a whole, using examples of how these may apply to dialysis and kidney disaster relief efforts in humanitarian settings.