The present study utilized an exploratory factor-analytic approach (i.e. principal-components analysis; PCA) to investigate whether the Social Concerns component of the Anxiety Sensitivity Index (ASI [Peterson, R. A., & Reiss, S. (1992). Anxiety Sensitivity Index manual (2nd ed.). Worthington, OH: International Diagnostic Systems.]) is best conceptualized as belonging to the domain of anxiety sensitivity (AS) and/or the domain of negative evaluation sensitivity (NES). A sample of university students (N = 216) was administered measures of both NES (i.e. Brief Fear of Negative Evaluation scale; Leary, 1983) and AS (i.e. ASI). Participants' responses to the items comprising these measures were subjected to a PCA with oblique rotation. Factors representing the NES construct and the three lower-order AS constructs (i.e. AS Physical, Psychological and Social Concerns) were obtained. Subscales derived from these four factors were positively and significantly correlated with one another and loaded on a single higher-order factor labeled Threat Sensitivity. Thus, the present findings suggest that the AS Social Concerns factor is distinct from NES and the other lower-order components of AS. However, correlational analyses and higher-order PCA indicated that the AS Social Concerns factor taps a blend of AS and NES as well as something unique and distinct from both global AS and NES.