Introduction: "Depressive disorder with mixed features" has been included in the official classification in the latest version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Hypothesizing that difficulties in emotion regulation and affective temperament scores are higher in mixed depression comparing to pure depression, we aimed to evaluate the relationship between these phenomena and mixed symptoms. Methods: Depressive patients diagnosed by a psychiatrist according to the DSM-5 and had not received any psychiatric treatment for the last 3 months, were included in the study. The Hamilton Rating Scale (HDRS), modified Hypomania Checklist (mHCL), Difficulties in Emotion Regulation Scale (DERS), and the TEMPS-A (Temperament Evaluation of Memphis, Pisa, Paris, San Diego Autoquestionaire) were applied to all participants. Results: Of the 63 participants, 40 (63.5%) were women. The mean age was 37.8±12.4 years while mean duration of education was 10.8±4.3 years. The proportion of mixed-depression assessed by the mHCL was 23.8% (n=15). No significant difference was found between the groups concerning gender, age, family history, age at onset of illness, the total number of episodes and temperament scores. Depressive patients with mixed features had significantly higher DERS nonacceptance subscale scores. Multiple regression analysis demonstrated that the cyclothymic temperament scale scores significantly affected the total mHCL scores. Conclusion: In mixed depression group, higher scores in nonacceptance subscale seems to reflect a tendency to fluctuations in the emotional reactions of a person to the stress. Association between mixed depression, DERS nonacceptance subscale and cyclothymic temperament support the spectrum view that mixed depression is placed between pure depression and bipolarity.