The conception of personality disorders (PDs) as distinct units of mental disorders is neither precise nor useful. At least some PDs, classified as separate units, reflect different behavioral expression of the same personality deviation. In this article we describe structural, developmental, and clinical continuum between relatively distinct entities of antisocial PD and narcissistic PD. The two disorders represent different endpoints sharing a borderline level of personality organization and pathological narcissism. We propose a spectrum relation for antisocial and narcissistic PD because the disorders tend to co-occur in the same individual and to run in the same family more often than expected by chance.