Objective: The aim of this study was to investigate the relationship between chronotype and temperament in patients with unipolar depression and the effect of chronotype on suicide risk. Methods: The participants consisted of patients with unipolar depression who were eligible for inclusion and exclusion criteria. Subjects were interviewed with the Structured Clinical Interview for DSM-5 and HAM-D, HAM-A scales. Patients filled the Morningness-Eveningness Questionnaire (MEQ), the Pittsburgh Sleep Quality Index, the Suicide Probability Scale and the Temperament Evaluation of Memphis, Pisa, Paris, San Diego Autoquestionnaire. Results: The participants were admitted female (n=69) and male (n=19). The rate of past suicide attempts was 24.1%. 50% of the patients had moderate depression and 50% of them had mild depression. According to MEQ scores patients were classified into three groups: 30.7% of them were eveningness, 58% of them were neither (intermediate) and 11.4 % of them were morningness type. The 90.8% of the patients had poor sleep quality. Depressive temperament was the most common temperament in the participants. Chronotype preference was not found to be associated with depression severity, anxiety, suicide probability, sleep quality, and temperament characteristics. Discussion: There was not an association between temperament and chronotype preferences. Chonotype preferences do not affect the severity of de-pression. Chronotype is not a risk factor for suicide. In assessing the risk of suicide in patients with mild to moderate severity depression without comorbid psychiatric disorders; the clinical characteristics of depression should be prioritized by the clinicians, rather than temperament and chronotype [Anadolu Psikiyatri Derg 2019; 20(5.000): 460-469]