To care can feel good, or it can feel bad. It can do good, it can oppress. But what is care? A moral obligation? A burden? A joy? Is it only human? In Matters of Care, Maria Puig de la Bellacasa presents a powerful challenge to conventional notions of care, exploring its significance as an ethical and political obligation for thinking in the more than human worlds of technoscience and naturecultures. Matters of Care contests the view that care is something only humans do, and argues for extending to non-humans the consideration of agencies and communities that make the living web of care by considering how care circulates in the natural world. The first of the book's two parts, Knowledge Politics, defines the motivations for expanding the ethico-political meanings of care, focusing on discussions in science and technology that engage with sociotechnical assemblages and objects as lively, politically charged things. The second part, Speculative Ethics in Antiecological Times, considers everyday ecologies of sustaining and perpetuating life for their potential to transform our entrenched relations to natural worlds as resources. From the ethics and politics of care to experiential research on care to feminist science and technology studies, Matters of Care is a singular contribution to an emerging interdisciplinary debate that expands agency beyond the human to ask how our understandings of care must shift if we broaden the world.