Individuals with borderline personality disorder (BPD) fear abandonment and exhibit instability in their close relationships. These interpersonal difficulties may be influenced by the propensity to interpret neutral social stimuli (e.g., nonemotional faces) as untrustworthy. This study evaluated the hypothesis that BPD features are associated with attributions of untrustworthiness to neutral faces. Additionally, the authors hypothesized that the trait of rejection sensitivity (RS) is also associated with BPD features and mediates the relationship between BPD features and untrustworthy facial trait appraisal. An undergraduate, nonclinical sample (N = 95) was assessed for BPD features, RS, and trust appraisal of neutral faces. Higher BPD features were associated with lower ratings of trustworthiness of the faces and higher scores on RS. Furthermore, as hypothesized, the association between BPD features and trust appraisal was mediated by RS. Results are discussed in the context of a proposed model of the social cognitive mechanisms of interpersonal hypersensitivity in BPD.