ABSTRACT Three types of close relationships have received attention from theorists and researchers interested in self-monitoring: friendships, romantic relationships, and marriage. Our review of this literature was organized around three phases of relationships: initiation, maintenance, and dissolution. Across the three types of relationships, consistent differences between high self-monitors and low self-monitors emerged concerning the structure of their social relationships (segmented vs. integrated), the basis for choosing friends and romantic partners (activity-based vs. person-based), and the orientation taken to romantic and marital partners (uncommitted vs. committed). Across all three types of relationships, however, little is known about the processes and consequences involved in the dissolution of close relationships for high self-monitors and low self-monitors. Relatively little is also known about the processes used by high self-monitors and low self-monitors to maintain their friendships and marriages. In addition to addressing these deficiencies in the literature, theorists and researchers interested in self-monitoring and close relationships need to develop sophisticated, causal models that can account for (a) interaction exchanges in the relationships, (b) dyadic as well as individual levels of analysis, and (c) temporal and situational changes in the course of close relationships.