Based on the premise that the experience of care is a fundamental component of motivation to learn, this paper explores the conceptual underpinnings of care within the contexts of teacher-student and peer relationships at school. Drawing from ecological and developmental traditions, theoretical models of caring relationships are discussed with respect to the transactional nature of dyadic relationships, representations of relationship affordances, and group-level relationship systems. Ways in which these perspectives are translated into commonly studied school-based constructs and assessments are then described. Finally, remaining issues and questions to guide further advances in theory and measurement are presented.