Introduction: The creation of measurement instruments are significant contributions to the measurement and advancement of scientific research. Objective: To design and validate a Thesis Advisor Abuse Scale (EMAT) in a sample of Peruvian thesis students. Methods: Instrumental design study where a scale of 20 items distributed in 3 factors (advisor, jury and administrative) was designed and validated. It had the participation of 274 thesis students (61.7% women). The Aiken V coefficient was used to analyze the evidence of content-based validity, the confirmatory factor analysis was used for construct validity, and reliability was studied through the Omega coefficient. Results: Adequate psychometric properties were obtained. The 20 items of the EMAT received a favorable evaluation through expert judgment, the confirmatory factor analysis supports the internal structure of 3 factors, reporting satisfactory goodness-of-fit índices, in addition, the correlation between factors was significant (P<.05) and the reliability acceptable. Conclusion: The EMAT is valid and reliable for measuring mistreatment of the thesis advisor.