Objective: Aggression is defined as the feeling of anger and the tendency to act destructively as a result of obstructing a behavior, and it is frequently seen today. The purpose of this study is to examine the psychometric properties of the Childrens Aggression Scale Teacher Form (CAS-T) and to adapt it into Turkish. The scale is the teacher version of the CAS-T, which has been examined in Turkey. The scale was developed to measure the severity, frequency, extent and diversity of aggressive behavior. Methods: The CAS-T Form consists of 23 items and five subscales. The scale was applied to the parents and teachers of 476 primary school students who showed aggressive behaviors and were directed to the child psychiatry clinic for diagnosis and treatment. For the validity of the scale, the relation was examined with similar scales. The difference between the groups was examined both in terms of diagnosis and gender, and confirmatory factor analysis was performed in the context of structure validity. For reliability, internal consistency is calculated. Conclusion: According to the findings of the research, it is thought that Turkish form of CAS-T Teacher Form is a reliable and valid measurement tool that can be used in the field of research and treatment. [Anadolu Psikiyatri Derg 2018; 19(0.100): 59-67]