This study investigated the indirect effects of problematic emotion regulation on features of Borderline Personality Disorder (BPD) when accounting for negative affect in 456 participants from two distinct geographic regions. Participants completed the Affect Intensity Measure (AIM), Difficulties in Emotion Regulation Scale (DERS), the Emotion Regulation Questionnaire (ERQ), and the Borderline Symptom List (BSL). Results from this study supported a model in which there were significant indirect effects of both a lack of emotional clarity and limited access to emotion regulation strategies on features of BPD when accounting for negative affective intensity. Results also supported a second model in which there were significant indirect effects of both limited access to emotion regulation strategies and difficulties engaging in goal-directed behavior on features of BPD when accounting for negative affective reactivity. The results highlight important inter-relationships among features of BPD, difficulties regulating emotions, and negative affective intensity and reactivity.