This article develops a scale of affects in opposite-sex relationships, and investigates affects of opposite-sex love, unrequited love, and friendship. In study 1 (N=231), a factor analysis of the affect items produced four factors: passion, affiliation-dissatisfaction, respect/trust, and aggressive/refusal. All scales were shown to be reasonably reliable (α>.80) In study 2 (N=295), the test-retest reliability coefficients ranged from .59 to .67. In study 3 (N=406), confirmatory factor analysis supported the four-factor structure. The results also showed that respect/trust was important for opposite-sex friendships. Affiliation-dissatisfaction was an important factor in unrequited love. Most important for lover relationships were passionate affects, respect/trust affects, and aggressive/refusal affects.