The aim of the current study was to compliment previous studies identifying negative states present in borderline personality disorder (BPD) by investigating the presence of positive affective and cognitive states. Ninety-six patients with criteria-defined borderline personality disorder and 24 axis II comparison participants completed the Positive Affect Scale, a 50-item self-report measure designed to assess positive stales thought to be characteristic of and discriminating for BPD. Seventeen positive states (4 affective, 10 cognitive, and 3 mixed) were found to be significantly more common among axis II comparison participants than borderline patients. Twelve of these states were common to both borderline patients and axis II comparison participants. Furthermore, four positive states, when co-occurring together, were particularly strongly associated with borderline personality disorder (three negatively and one positively): (a) Fond of myself, (b) That things around me are real, (c) That I've forgiven others, and (d) Assertive. Finally, the overall mean score on the PAS significantly distinguished patients with borderline personality disorder from axis II comparison participants. Taken together, these results suggest that borderline patients are far less likely to report experiencing positive states of an affective, cognitive, and mixed nature than axis II comparison participants. They also suggest that being assertive is a positive state particularly discriminating for borderline personality disorder.