Many have argued that it is important to examine different aspects of commitment in romantic relationships, but few studies have done so. Using a large, national sample of unmarried adults in relationships (N = 1184), this study examined four aspects of relationship commitment and their associations with relationship adjustment and stability. We examined dedication (i.e., interpersonal commitment) as well as three types of constraint commitment: perceived constraints (e.g., social pressure to stay together or difficulty of termination procedures, measured using Stanley and Markman’s [1992] Commitment Inventory), material constraints (e.g., signing a lease, owning a pet), and felt constraint (i.e., feeling trapped). Cross-sectionally, these four facets of commitment were associated in expected directions with relationship adjustment, as well as perceived likelihood of relationship termination and of marriage. Longitudinally, each facet uniquely predicted relationship stability. More dedication, more material and perceived constraints and less felt constraint were uniquely associated with a higher likelihood of staying together over an 8-month period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)