Objectives: To localize the textual interface of the Sure Wash Pocket® mobile health app and to present the methodological experience used in the localization process. Method: Software localization study to Brazilian Portuguese. The localization process was carried out between December 2018 and June 2019 in the city of Cuiabá/MT, through six steps: permission to localize the software; two independent translations; synthesis of translations; evaluation of the validity of the textual interface by a Committee of Expert Judges; back translation; and publication. Results: The textual interfaces were organized into 107 items and analysed by ten expert judges. In the first round, 64% of the items reached a pre-established minimum agreement level of 90%. During the second round, 39 remaining items were adapted according to consensual suggestions and the pre-final version was consolidated. Conclusion: The localization process suggests that the localized SureWash Pocket® is considered valid and can be used for an educational intervention on hand hygiene.