The interdisciplinary study of relationships has begun to frame several issues important for advancing an understanding of interpersonal processes. This article addresses the contribution to this effort that can be made by personal construct theory (Kelly, 1955) and its related methodology. In particular we argue that construct theory can help illuminate (1) the complex interconnectedness between the self and its social context, (2) the multiple trajectories that relationships can follow, and (3) the processes associated with relationship disorder and deterioration. Situated at the interface of social and clinical psychology, construct theory is strategically located to advance our understanding of a broad range of psychosocial processes entailed in personal relationships. Applications of the theory to several concerns in the larger literature are discussed, and directions for research are illustrated.