Internalized transphobia (IT) is influenced by societal norms and expectations, and it can have significant negative effects on the well-being and mental health of transgender individuals. The aim of this study was to translate and evaluate the psychometric properties of the Persian 8-item IT scale among Iranian transgender individuals in order to enhance the quality and quantity of research in this field. This cross-sectional and methodological study utilized convenience sampling to recruit 119 transgender individuals in Mashhad, the second most populous city in Iran, in 2021. The Persian translation of the IT scale was developed using the backward-forward translation method. Subsequently, various types of validity and reliability were assessed, including content validity using the content validity index (CVI) and content validity ratio (CVR), face validity based on the impact score, construct validity through confirmatory factor analysis (CFA), internal consistency measured by Cronbach's alpha, and test-retest stability analyzed using the intraclass correlation coefficient (ICC). The CVR ranged from 0.600 to 1, the CVI ranged from 0.800 to 1, and the impact score exceeded 1.5, indicating the appropriate content and face validity of the 8-item IT scale. The construct validity analysis revealed that the questionnaire is one-dimensional. The internal consistency, as measured by Cronbach's alpha, was 0.917, and the ICC for test-retest stability was 0.871. The Persian version of the IT scale demonstrated high and acceptable psychometric properties. The brevity of this scale facilitates its dissemination and utilization in clinical settings.