Borderline Personality Disorder (BPD) has long been considered a mental health problem that results in considerable costs in terms of human suffering and psychiatric expenses among adult patients. Although the diagnosis of BPD for adolescents is frequently used in clinical settings, the field of mental health has questioned whether one should diagnose BPD among adolescents. This paper reviews the recent empirical literature (identified through PsycINFO 1980 to present) to evaluate prevalence, reliability, and validity of a BPD diagnosis in adolescents. It is concluded that the features BPD diagnoses in adolescents are comparable to those in adults. Furthermore, there appears to be a legitimate subgroup of adolescents for whom the diagnosis remains stable over time as well as a less severe subgroup that moves in and out of the diagnosis. While caution is warranted, formal assessment of BPD in adolescents may yield more accurate and effective treatment for adolescents experiencing BPD symptomatology. More longitudinal research is necessary to further explicate the issues of diagnosing BPD in adolescents.