Preliminary evidence suggests that biased attention could be crucial in fostering the emotion recognition abnormalities in borderline personality disorder (BPD). We compared BPD patients to Cluster-C personality disorder (CC) patients and non-patients (NP) regarding emotion recognition in ambiguous faces and their visual attention allocation to the eyes. The role of comorbid posttraumatic stress disorder (PTSD) in BPD regarding emotion recognition and visual attention was explored. BPD patients fixated the eyes of angry/happy, sad/happy, and fearful/sad blends longer than non-patients. This visual attention pattern was mainly driven by BPD patients with PTSD. This subgroup also demonstrated longer fixations than CC patients and a trend towards longer fixations than BPD patients without PTSD for the angry/happy and fearful/sad blends. Emotion recognition was not altered in BPD. Biased visual attention towards the eyes of ambiguous facial expressions in BPD might be due to trauma-related attentional bias rather than to impairments in facial emotion recognition.