Taddeo Alderotti’s Libellus conservande sanitatis can be found in several manuscripts, both in Latin and in vernacular. It is generally maintained that Alderotti wrote the text in vernacular and later translated it himself into Latin. This study lists the manuscripts, adding new findings and distinguishing three different vernacular versions. In the light of a close comparison, it argues that it is more likely that the Latin text is the original one, and that it was not translated into vernacular by its author. Finally, it analyses the texts transcribed alongside the three vernacular versions, in order to show their various adaptations of Alderotti’s work.