Previous research indicates that adults believe that sexual desire and sexual activity play different roles in love relationships. Little research, however, has been conducted to document the presumed differences between these two aspects of human sexual response. The purpose of this study was to examine empirically (1) whether sexual desire and sexual activity co-occur in dating relationships; (2) whether desire is more strongly associated than activity with passionate love; and (3) whether desire and activity have different implications for relationship maintenance. The results revealed that sexual desire and sexual activity were moderately (but not significantly) related. In addition, and as expected, only sexual desire was related to passionate love. Sexual desire also was related to relational maintenance; the greater the desire for the partner, the less often participants thought about ending their current relationship, thought about beginning a new relationship, reported being unfaithful to their partner, and felt attracted to others.