Modern diagnostic and classification frameworks such as the ICD-11 and DSM-5-AMPD have adopted a dimensional approach to diagnosing personality disorder using a dual “severity” and “trait” model. As narcissistic personality has historically struggled to be adequately captured in dominant diagnostic systems, this study investigated the utility of the new ICD-11 framework in capturing diverse narcissistic expressions. Participants were mental health clinicians (N = 180, 67% female, age = 38.9), who completed ratings of ICD-11 personality severity, trait domains and a clinical reflection for two hypothetical case vignettes reflecting either prototypical “grandiose” or “vulnerable” narcissism. The majority of clinicians (82%) endorsed a diagnosis of personality disorder for both grandiose and vulnerable vignettes. Discriminant elements of personality impairment included rigid, unrealistically positive self-view, low empathy and high conflict with others for grandiosity, and incoherent identity, low self-esteem and hypervigilant, avoidant relations with others for vulnerability. Regarding trait profile, grandiose narcissism was predominately dissocial whereas vulnerable narcissism was primarily associated with negative affectivity and detachment. Qualitative responses highlight distinct clinical themes for each presentation. These findings suggest that clinicians using the ICD-11 framework are able to identify common core elements of personality dysfunction in grandiose and vulnerable narcissism while also recognizing their distinctive differences.