Objective: This study demonstrates the reliability and validity of the Turkish Form of Acute Stress Symptoms Scale which was developed according to DSM-5 criteria to measure the severity of acute stress disorder. Methods: This research was carried out with the patients who fulfilled the criteria of any stress related disorders according to DSM-5 criterion in inpatient and outpatient psychiatric clinics of Celal Bayar University, School of Medicine. Except for acute or post-traumatic stress disorders, patients with any other mental or physical disease were excluded. Fifty patients were included in the study. As the control group, 150 volunteers without any mental or physical diseases were invited. Beside Acute Stress Symptoms Scale, Peritraumatic Dissociative Experiences Questionnaire (PDEQ) which is the most commonly used self-rated instrument to rate the experience of recent trauma is utilized for concur-rent validity. In reliability analyses, internal consistency coefficient and item-total correlation coefficients were calcu-lated. In validity analyses, factor analysis and correlation analysis with PDEQ were performed. Results: The mean age of the study group was 32.1±12.0 years, and 57.7% of the sample group (n=116) were female. 31.3% of the group were college graduates, 36.3% primary school graduates, 29.9% is high school graduates. Disease duration in acute stress disorder group was 4.08±4.57 years. For the internal consistency of Acute Stress Symptoms Severity Scale, Cronbachs alpha coefficient was found to be 0.95. Item-total score correlation coefficients were between 0.76 and 0.88 and all were statistically significant. For the exploratory factor analysis, sample adequacy was tested, Kaiser-Meier-Olkin (KMO) coefficients was 0.91 and Bartlett coefficient was 1388. Single-factor solution was obtained and the eigenvalue was 5.40, representing 77.8% of the total variance. Factor loadings of the items were between 0.82-0.92. The coefficient of correlation analysis with PDEQ was calculated as r=0.88. Area under the curve is found 0.99 as the result of ROC analysis. Conclusion: With these findings, it is shown that the severity of Acute Stress Symptoms Scale is reliable and valid for Turkish. [Anadolu Psikiyatri Derg 2017; 18(0.200): 38-44]