ABSTRACT Aim: This study demonstrates the reliability and validity of the Turkish form of repetitive Thoughts and Behaviors Scale which is developed according to DSM-5 criteria to measure the severity of obsessive-compulsive disorders. Method: This research was carried out with the patients who fulfilled the criteria of obsessive-compulsive disorders according to DSM-5 criterion in inpatient and outpatient psychiatric clinics of Celal Bayar University, School of Medicine. Except for obsessive-compulsive disorders patients with any other mental or physical diseases were excluded. Thirty patients were included in the study. As the control group, 30 volunteers without any mental or physical diseases were invited. Beside Repetitive Thoughts and Behaviors Scale, Maudsley Obsession and Compulsion Questionnaire which is the most commonly used self-report scale was used for concurrent validity. In reliability analyses, internal consistency coefficient and item-total correlation coefficients were calculated. In validity analyses, factor analysis and correlation analysis with MOCQ were performed. Results: The mean age of the study group was 31.2 ± 9.7, and 65% of the sample group (n = 39) were female. 56.7% of the group were college graduates, 18.3% primary school graduates, 25% high school graduates. Disease duration in the obsessive-compulsive disorder group was 7.5 ± 6.1 years. The internal consistency of the Repetitive Thoughts and Behaviors Scale 0.97 and, item-total correlation coefficients of the Repetitive Thoughts and Behaviors Scale 0.86-0.95 (p [Anadolu Psikiyatri Derg 2017; 18(0.200): 18-23]