Impairments in interpersonal relationships are a core feature of borderline personality disorder (BPD). Social cognition dysfunction, like false recognition of others' emotions and intentions, may lead to emotional disturbances, self-injury, and impulsive aggression behaviors in patients with BPD. This study explored the extent to which social cognition, including emotional recognition and theory of mind (ToM), can predict the ability of social awareness in patients with BPD. Emotion recognition tasks (matching emotional facial expressions to prosody), verbal and nonverbal theory of mind tasks, and the awareness of social inference test were assessed. Results of a stepwise multiple regression showed that the quality of the early parent-child relationship, anger prosody recognition, and ToM were significantly related to the ability to be aware of social interactions in the patients with BPD.