Self-report scales assessing relationship-specific incentive and threat sensitivity were created. Initial tests of factor structure and associations with relationship quality were conducted in a sample of persons in intimate relationships (Study 1). Associations with conceptually related measures were examined to determine convergent and discriminant validity in a sample of dating couples (Study 2). Cross-validation of the factor structure was established in engaged couples (Study 3) and in newlywed couples (Study 4). In Study 4, couples also engaged in a laboratory-based threat task (discussion about a significant marital problem) and incentive task (discussion about loving aspects of the partner/marriage). Relationship incentive sensitivity predicted higher positive affect after the incentive task for both husbands and wives. Relationship threat sensitivity predicted greater anxiety in response to the threat laboratory task for wives only. Implications of approach and avoidance motivations in close relationship processes and outcomes are discussed. (Contains 4 tables and 3 footnotes.)