Background: Research into the personality trait of narcissism have advanced further understanding of the pathological concomitants of grandiosity, vulnerability and interpersonal antagonism. Recent research has established some of the interpersonal impacts on others from being in a close relationship with someone having such traits of pathological narcissism, but no qualitative studies exist. Individuals with pathological narcissism express many of their difficulties of identity and emotion regulation within the context of significant interpersonal relationships thus studying these impacts on others is warranted. Method: We asked the relatives of people high in narcissistic traits (indexed by scoring above a cut-off on a narcissism screening measure) to describe their relationships (N = 436; current romantic partners [56.2%]; former romantic partners [19.7%]; family members [21.3%]). Participants were asked to describe their relative and their interactions with them. Verbatim responses were thematically analysed. Results: Participants described 'grandiosity' in their relative: requiring admiration, showing arrogance, entitlement, envy, exploitativeness, grandiose fantasy, lack empathy, self-importance and interpersonal charm. Participants also described 'vulnerability' of the relative: contingent self-esteem, hypersensitivity and insecurity, affective instability, emptiness, rage, devaluation, hiding the self and victimhood. These grandiose and vulnerable characteristics were commonly reported together (69% of respondents). Participants also described perfectionistic (anankastic), vengeful (antisocial) and suspicious (paranoid) features. Instances of relatives childhood trauma, excessive religiosity and substance abuse were also described. Conclusions: These findings lend support to the importance of assessing the whole dimension of the narcissistic personality, as well as associated personality patterns. On the findings reported here, the vulnerable aspect of pathological narcissism impacts others in an insidious way given the core deficits of feelings of emptiness and affective instability. These findings have clinical implications for diagnosis and treatment in that the initial spectrum of complaints may be misdiagnosed unless the complete picture is understood. Living with a person with pathological narcissism can be marked by experiencing a person who shows large fluctuations in affect, oscillating attitudes and contradictory needs.