This paper aims to analyse the translation, by the authors of this work, of de Erauso’s autobiography to contemporary Brazilian Portuguese. Written in the 17th century and first published two centuries after under the title of Historia de la monja alférez, the book tells de Erauso’s life, who was a soldier of the Spanish Empire until his sex was revealed. He was deported to Europe and received an authorization from the Pope to continue with his assumed gender identity. Considering the discussions from today on gender identity and queer translation studies, our translation is a critical actualization of the text by recognizing the character as a trans man. For this, this paper will explain the translating choices by means of comparison to Ferrer’s edition (1829), and Stepto’s translation (1996) to English, so that Erauso’s identity will be affirmed in opposition to the female one that the critique has consolidated. This work, thus, is relevant by the resignification of the text, respecting its documental and historical aspect and discussing the possibilities of gender.