Background: The validity of borderline personality disorder (BPD) has been a topic of much controversy in psychiatry. Over the last two decades, a wealth of empirical work has challenged long-held concerns regarding the validity of adolescent BPD. However, this research has been conducted within a traditional approach to psychiatric nosology. Objective: In this article, we aim to evaluate the validity of adolescent BPD as guided by both the Robins and Guze criteria for the validity of psychiatric constructs and the new National Institute of Mental Health Research Domain Criteria (NIMH RDoC). Method: We used the five principles of the Robins and Guze approach to evaluate selected research from our own and other groups regarding the validity of adolescent BPD. These principles include clinical description studies, laboratory studies, studies that delimitate the disorder from other related syndromes, follow-up studies, and family studies. Results: Within the Robins and Guze criteria framework, evidence to date supports the validity of adolescent BPD to some extent. However, limitations of the research about the construct validity of adolescent BPD have also been identified, most notably regarding the delimitation of adolescent BPD from other disorders as well as a lack of longitudinal and family studies. Conclusions: Given these limitations and the limitations of the Robins and Guze approach to psychiatric nosology, we recommend exploring the potential of the National Institute of Mental Health Research Domain Criteria as a complement to previous work.