Objective: To develop and validate a questionnaire to measure the vulnerability of orthodontists, measuring the risks of being involved in civil liability lawsuits. Material and Methods: In-depth interviews were performed with three groups: G1-law professionals, G2 -orthodontists, and G3 -orthodontic patients. From the analysis of the content of Bardin, domains for the construction of the first version of the 53-question questionnaire were identified. The questionnaire was submitted to experts for validation, inclusion and exclusion of questions, but maintaining the 53-question format. It was submitted to the testretest phases and verification of internal consistency. Results: 247 professionals answered the final version of the questionnaire. The intraclass correlation coefficient was 88.8%. Cronbach's alpha was 0.946, with high internal consistency. The Kaiser-Meyer-Olkin and Bartlett's tests confirmed internal consistency showing the values of 0.909 and significance of <0.001, respectively. From the total score and factorial analysis, the sample was divided into three groups of judicial vulnerability. Conclusion: The results of this study demonstrated that the questionnaire is a valid tool to measure the risks of involvement in civil liability lawsuits by orthodontists. It presented a multidimensional character and might be applied as well as face to face or online, without prejudice to quality.