The article presents a comparative analysis of three translations of the famous epistle sent by Saint Jerome to his friend Pammachium, in which the author reflects on the nature of translation. The author selected a Spanish, an Italian and a Portuguese version, and has compared them in order to determine the degree of adherence to Saint Jerome's thesis. With this aim, particular examples have been selected to contrast the solutions adopted by the different translators. The author has tried to determine the reasons that led the translator to this particular option, according to the date of publication, the original function, the translator's notes or the references made to previous studies of the same work.