The relationship between childhood sexual abuse and borderline personality disorder is a prominent issue in the etiological research on borderline personality disorder. This study further explored the relationship between childhood sexual abuse and the development of borderline personality features while evaluating the moderating role of a primary social support source in a sample of 290 female undergraduate students enrolled at a major southeastern university. Consistent with previous research, retrospective self-reports of childhood sexual abuse and low social support were both positively correlated with current borderline personality features. It was hypothesized that the presence of a supportive relationship at the time the childhood sexual abuse occurred would moderate the relationship between childhood sexual abuse and borderline personality features. This moderation hypothesis was not supported in the current study, but post-hoc analyses reveal the need to further examine how we define social support following childhood sexual abuse. This research is a stepping stone toward the prevention of borderline personality disorder following childhood sexual abuse. (Contains 2 tables.)