Objective to translate and culturally adapt the Patient Measure of Safety questionnaire to Brazilian Portuguese. Method a transcultural adaptation study conducted in six stages: translation, synthesis, back-translation, review by experts committee, pre-test, and presentation of the documentation of the entire process to the authors of the instrument. Results in the initial translation and cultural adaptation stage, two versions of the questionnaire were generated. The divergences between both versions and other suggestions were discussed, and the decisions were made by consensus, thus creating a single version. In the back-translation stage, there were no significant differences between the versions and the original instrument. The assessment of the semantic, idiomatic, cultural and conceptual equivalences of the Patient Measure of Safety items was performed by a committee of experts from different Brazilian regions. The results of the content validity index were above 0.9 for most of the items. The pre-test was conducted with 30 patients. The mean time for the application of the questionnaire was 31.9 minutes. In relation to the understanding of the items by the patients, a regular or poor interpretation was identified only for 6 of the 44 items, which were modified. Conclusion the “Questionário de Avaliação da Segurança pelo Paciente”, name given to the translated and transculturally adapted version, resulted from a thoughtful process, presenting consistency in the equivalence of the translation and constituting an applicable instrument understood by the target population.