Objective In this study, we aimed to determine clinical correlates of false positive assignment (FPA) on commonly used bipolar screening questionnaires. Methods A retrospective chart review was conducted to a total of 3885 psychiatric outpatients. After excluding patients who have bipolar spectrum illnesses, patients who were assigned as having hypomania on the mood disorder questionnaire (MDQ) or the hypomania checklist-32 (HCL-32) were identified as patients who had FPA. Psychiatric diagnoses and severity of emotional symptoms were compared between patients with and without FPA. Results Patients with FPA on the MDQ showed significant associations with presence of major depressive disorder, generalized anxiety disorder, and alcohol-use disorder, while patients with FPA on the HCL-32 showed associations with presence of panic disorder and agoraphobia. FPA on the MDQ was also associated with greater emotional symptoms and lifetime history of suicide attempts. Logistic regression analysis showed that male sex, younger age, presence of alcohol-use disorder, and severity of depression and obsessive-compulsive symptoms were significantly associated with FPA on the MDQ. Conclusion The FPA for the MDQ was associated with clinical factors linked to trait impulsivity, and the FPA for both the MDQ and the HCL-32 could be related to increased anxiety.