Objective: Borderline personality disorder (BPD) is characterized with emotional, cognitive, behavioral disorders, and its manifestation becomes evident in adolescence or early adulthood. According to Linehan's biosocial theory, emotion dysregulation (ED) is a core feature of BPD. Self-esteem (SE) is known to be associated with borderline symptom severity and depression in BPD. In our study, we aimed to investigate the relationship between ED, SE and negative affect. Methods: Twenty-six patients with BPD and 26 healthy controls were included. Sociodemographic data form, Cognitive Emotion Regulation Questionnaire (CERQ), Difficulties in Emotion Regulation Scale (DERS), Rosenberg Self-Esteem Scale (RSES), Positive and Negative Affect Scale (PANAS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) were our evaluation tools. Results: No difference was found between the groups in terms of age, gender, education and marital status. The total and subscale scores of the DERS, the negative affect subscale of the PANAS (PANASn), the RSES were found to be significantly higher in BPD than healthy controls. Predictors of depression in the linear regression analysis were negative affect (PANASn), and predictors of SE (RSES) is depression. Emotion dysregulation (DERStotal) was the predictive vari-able of negative affect (PANASn). Conclusions: In our study, DDG was predictor of negative affect and it was observed that emotion dysregulation itself contributed to negative affect in addition to the innate emotional sensitivity. The predictive effect of ER on negative affect was thought to be triggered by dysregulating behavior. No relationship was found between ER and SE because of evaluating ER state and SE trait. It would be appropriate to evaluate whether DDG has an effect on self-esteem with large sample studies in the future.