Objective: Establishing a diagnosis of Borderline Personality Disorder (BPD) in adolescents is often met with controversy, in part, due to potential stigmatizing effects. We wished to explore the adolescent patient experience of being diagnosed with BPD. Method: The Impact of Diagnosis Scale (IODS) is a self-report measure we developed with questions targeting patients' subjective experience of receiving a diagnosis of BPD. The IODS was administered to 23 adolescents approximately one month after a diagnosis of BPD had been disclosed to them. Results: Twenty-one participants had analyzable data. The internal consistency of the measure demonstrated Cronbach's alpha of 0.66. We found wide variability in responses. Patients tended to view the diagnosis as an accurate representation of their symptoms. Conclusion: The IODS represents a novel means by which clinicians might better appreciate how disclosing the diagnosis of BPD may impact a patient's understanding of one's difficulties.