The purpose of this study is to develop a valid and reliable scale that identifies school principles 'trust in teachers based on the perceptions of teachers. The study was conducted on three separate study groups for the purposes of performing the exploratory factor analysis, confirmatory factor analysis and test-retest correlation of the scale. The study group for the exploratory factor analysis consisted of 264 teachers, while the confirmatory factor analysis consisted of 242 teachers and the study group for test-retest correlation consisted of 28 teachers. As part of the validity studies, a content and structural validity assessments were performed. In order to ensure content validity, interviews were held with school principals and teachers; the literature was reviewed and the statements included in the assessment tool were submitted for the opinion of experts and teachers. Exploratory and confirmatory factor analyses were performed for ensuring structural validity. As part of the reliability studies, Cronbach Alpha reliability and item-total correlations were used for ensuring internal consistency, while the test-retest correlation for ensuring internal consistency over time. It was established that the scale had a four factor structure consisting of a total of 18 items. The values obtained from confirmatory factor analysis suggested that the model-data congruence was at an acceptable level for the scale. As a result of the analyses conducted as part of the scale reliability studies, the Cronbach Alpha internal consistency coefficient was calculated as ".916 " for the competence dimension, as ".861 "for the trustworthiness dimension, as ".793 " for the openness dimension and as ".755 "for the helpfulness dimension. The testretest reliability (Pearson correlation) coefficient of the scale was calculated as ".870 " for the competence dimension, as ".848 "for the trustworthiness dimension, as ".918 " for the openness dimension and as ".806 "for the helpfulness dimension. The findings obtained as a result of the validity and reliability studies suggest that the scale developed can be used as a valid and reliable assessment tool in evaluating school principals 'trust in teachers based on teachers 'perceptions.