The aim of this study was to evaluate the structure of pathological narcissism and its relationships with adult attachment styles in 394 Italian nonclinical volunteers and in 103 consecutively admitted Italian outpatients. All participants were administered the Pathological Narcissism Inventory (PNI) and the Attachment Style Questionnaire (ASQ). Confirmatory factor analyses replicated the 2-factor model of the PNI found in English-speaking samples in both nonclinical and clinical samples. Structural equation models showed that adult attachment insecurities were characteristically associated with the PNI Narcissistic Vulnerability scale, whereas the PNI Narcissistic Grandiosity scale was positively associated with the ASQ Confidence scale in both samples. Overall, our findings support the hypothesis that pathological narcissists are both vulnerable and grandiose and suggest that assessing adult attachment may be important in understanding pathological narcissism in adults.