INTRODUCTION: The ToxBH-NM scale, which assesses toxic leadership behaviors in nurse managers, is a questionnaire specifically developed for this purpose. The necessity for further research to identify and evaluate toxic leadership styles in Iranian contexts underscores the significance of possessing a valid and reliable measurement questionnaire in Persian. This study aims to assess the psychometric properties of the Persian version of the ToxBH-NM among Iranian nurses. METHODS: A methodological study was conducted in 2024 with a sample of 359 nurses, selected through convenience sampling from various hospitals in Hamadan city. After translating the questionnaire, construct validity was evaluated in two phases. The first phase involved exploratory factor analysis, while the second phase applied confirmatory factor analysis. In addition, reliability was assessed by measuring the internal consistency of the questionnaire using statistical tests such as Cronbach's alpha and McDonald's Omega. RESULTS: Exploratory factor analysis identified a structure with 25 items across three factors, accounting for 67.6% of the total variance. Confirmatory factor analysis demonstrated an adequate model fit, and subsequent statistical tests confirmed the reliability of the questionnaire as acceptable. CONCLUSION: The study findings indicate that the Toxic Leadership Behaviors Questionnaire demonstrates satisfactory validity and reliability, supporting its suitability as a questionnaire for assessing toxic leadership behaviors among nursing managers in Iran.