This study examined the associations between relationship qualities, sexual behaviors, and relationship length in 61 adolescent couples (aged 16-20). For both male and female partners, positive relationship qualities were associated with physical expressions of affection. Perceptions of higher levels of conflict and frustration were associated with more frequent sexual intercourse. Factor analysis and multiple regression indicated that the frequency of sexual behavior and the perception of global relationship quality (support, depth and intimacy) predicted relationship length for these couples. While the frequency of sexual expression was associated with relationship longevity for both male and female partners, positive relationship qualities (depth and intimacy) were additionally associated with relationship longevity for male partners only. Implications of these findings are discussed in light of current gaps in understanding the relational context of adolescent sexual behavior.