Mentalization is proposed to underlie the disturbed interpersonal relatedness that is a hallmark of borderline personality disorder (BPD). Despite growing evidence of BPD in adolescents, studies examining mentalization in relation to adolescent BPD have remained limited. Given contradictory findings of this relationship, particularly with adults, further research of mentalization in adolescents with BPD is warranted. The current study further clarifies the nature of mentalizing impairments, related to BPD, by examining different aspects of mentalization between adolescents with BPD (n = 26) and a group of healthy controls (n = 25). Findings support studies that suggest that mentalization may be an important treatment target, influencing BPD symptoms and interpersonal functioning in adolescents with BPD. They also support the importance of examining mentalizing abilities in relation to varying levels of complexity, interpersonal contexts, and levels of arousal. Limitations and further research are discussed.