Objective: cultural adaptation and validation of the Moral Sensitivity Questionnaire to assess moral sensitivity among Brazilian nurses. Method: methodological study with 106 nurses from two hospitals located in the south of Brazil. The instrument was culturally adapted according to international guidelines, following six steps: translation, reconciliation of translated versions, back translation, expert panel, pretest, and final review. The Brazilian version was validated in the Brazilian context using factor analysis and Cronbach’s alpha. Results: after the expert panel’s assessment, pretest, and verification of face and content validity, the instrument was considered satisfactory to be applied among Brazilian nurses. Six constructs were identified: Respect for patients’ autonomy, modified autonomy, experiencing moral conflict, having confidence in medical and nursing knowledge, structuring moral meanings, and teamwork. The instrument presented satisfactory internal consistency, with a Cronbach’s alpha equal to 0.62; the Cronbach’s alpha of the six constructs ranged from 0.60 to 0.67. Conclusion: the Brazilian version of the Moral Sensitivity Questionnaire is valid and reliable to be applied among Brazilian nurses and can improve understanding of factors involving decision-making when facing ethical conflicts.