This book addresses the central issue of children’s social situation of development in relation to sustainability, care and imagination. The concept of sustainability is topical in current societal discussions, but much in need of further elaboration, which is provided by this book as an integrated aspect of childcare and child development. It provides an exploration of whether and how sustainability can contribute relevantly to conceptual development within the cultural-historical framework with relation to child development more broadly and care and imagination more specifically. A central question in the book is how the concept of sustainability is related to Vygotsky’s writings on the zone of proximal development and the social situation of development. It takes on the current need to understand the problem of creating more sustainable societies and practices as interconnected practices for supporting the development of children as present and future sustainability-responsible citizens. This book provides a much needed theoretical elaboration of child care as a scientific concept, the practice context of care, and a wholistic conceptual approach to care.