In this study, it was aimed to compare the consistency between the scores of both the parents and teachers of the same children according to different techniques for the four scales commonly used in the literature in measuring the degree of the disorder in children with autism spectrum disorder (ASD), and in the evaluation of repetitive behaviors and social communication-interaction behaviors, which are the leading indicators of the disorder. Participants of this study, which is a relational survey model, are the individuals diagnosed with ASD, between the ages of 3-23 (and N between 300 and 380), and attending schools and rehabilitation centers affiliated with the Ministry of National Education in the 2018-2019 academic year, as well as their parents (N between 292 and 379) and teachers (N between 298 and 378). Four different scales were used to evaluate the behavioral and developmental characteristics of children with ASD in the study. As a result of the research, it was seen that the scores obtained from parents and teachers, who completed different scales, were high in internal consistency within groups. Moreover, in some subscales, the difference between the reliability coefficients regarding the scores obtained from parents and teachers was statistically significant in favor of teachers. It was determined that the correlations regarding the scores obtained from the parents and teachers differed according to the subscales (low, medium, high level, and non-significant relationship). In this context, it was also found that it is not appropriate to interpret the consistency between parents and teachers based only on correlations.