Psychopathy is a collection of personality traits and behaviors that are associated with costly personal, interpersonal, and societal outcomes. The nature of this construct has been widely debated across decades of literature, and such debates have produced a multitude of instruments for the measurement of psychopathy. These measures include self-reports and clinical interviews, yet little work has examined the degree to which measurements of psychopathy may differ across these modalities and whether such potential differences may impact the associations commonly found with psychopathy (e.g., impulsivity). To this end, we applied psychometric network and item response theory analyses to data obtained from the interview-based Psychopathy Checklist: Screening Version and the Levenson Self-Report of Psychopathy in the same sample. Our results revealed similarities and differences across measurement modalities. Regarding the Psychopathy Checklist: Screening Version, Factor 2 items were more important to the psychopathy construct (i.e., the most central and contributed more information than Factor 1 items), whereas Factor 1 items were more important to the Levenson Self-Report of Psychopathy. Factor 1 items were positively linked with Positive Urgency and were either negatively associated or not associated with Negative Urgency. In contrast, Factor 2 items were positively linked with Negative Urgency in both networks. Our analyses also revealed that dishonesty and irresponsibility served as the primary bridges connecting the factors of psychopathy in both networks. We make suggestions for improving the assessment of psychopathy by implementing self-report and interview measures that allow scores to be compared directly. (PsycInfo Database Record (c) 2023 APA, all rights reserved).