Objective: This study aims to demonstrate the reliability and validity of Turkish version of DSM-5 Level 2 Depression Adult Scale which was developed to measure the severity of depression. Material-methods: The study group included 51 in or out-patients who met the criteria for major depressive disorder according to DSM-5. Sixty-five volunteers without any mental or physical disease were also recruited as a control group. Beck Depression Inventory (BDI), which is the most widely used self-report scale, was used for concurrent validity. Internal consistency coefficient and item-total correlation analysis were performed for reliability. Exploratory factor analysis was used for validity, as BDI was used for concurrent validity. Results: Mean age was 40.5±11.4 in the patient group and 21.8±4.9 years in the control group, respectively. 62.1% of the sample group(n=72) were female. 59.5% of the group were college graduates, 16.4% were primary school graduates and 14.7% were high school graduates. Disease duration for major depressive disorder was 13,5±10,5 years for the patient group. The internal consistency of the Level 2 Depression Adult was 0.96. Item-total correlation coefficients were between 0.71-0.90 (p [Anadolu Psikiyatri Derg 2017; 18(0.200): 57-62]