This article explores the influence of relationships on student achievement by examining empirical evidence and by adopting a social psychological theory. Initially, the issue is addressed from a national, Swedish context. Thereafter, two general questions are raised: (1) What is the influence of relationships on student achievement, according to empirical research? (2) How can the influence of relationships on student achievement be conceptualised? Question one is discussed from a body of international and Scandinavian research on general characteristics of teaching that promote student achievement. The argument leads to a model in which the teacher-student relationship is a key factor. In order to discuss the second question, Kenneth Gergen's social psychological theory is applied. According to the analysis, relationships play an essential role in understanding student achievement. The relational process is regarded as an inherent aspect of educational life and the foundation for encouraging performance. By combining these perspectives, the significance of relationships for comprehending student achievement is revealed. In the final section of this text, practical-pedagogical implications are discussed with reference to a narrative about a young student's knowledge development. (Contains 3 notes.)