Abstinence as a protection against STD and unwanted pregnancy is highly promoted by public health and health education professionals. However, few studies of abstinence have focused on abstinence within the context of partnerships, particularly as relationships change over time. Understanding the factors that predict abstinence states and how those states may change over time is important to understanding sexual decision-making. In this longitudinal study of 365 young women, the influence of relationship quality, motivations for coitus, sexual relationship satisfaction, sexual self-efficacy, sexual conservatism, and religiosity were evaluated in a static model using cross-sectional data from enrollment and in a state change model using longitudinal data. All measures were partnership specific with the exception of sexual conservatism and religiosity. The main study hypothesis was that relationship quality is associated with abstinence state and influences state change within partnerships. Age, relationship quality, motivations for coitus and sexual relationship satisfaction were all negatively associated with abstinence while sexual conservatism had a positive association in the static model. State change from sexually active to abstinent was associated positively with sexual conservatism and negatively with age, sexual desire and relationship quality. For transitions from abstinent to sexually active, the direction of the association for age and sexual conservatism was reversed and relationship quality and sexual desire were no longer a significant factors. Understanding abstinence within the context of partnerships is useful for the development of programs designed to promote healthy sexual decision-making. Important findings from this study were that understanding of relationship quality may result in more appropriately targeted education and intervention messages; sexual conservatism may be a more important construct than religiosity for promotion of abstinence; and, understanding sexual desire and other motivations for coitus within partnerships may provide useful information to health practitioners.