First of all, we have made a transcription of the most important Mediaeval inscriptions in Latin which are in Zamora, from the tenth to the fifteenth century. The succeeding graphematic-phonetic and morphosyntactic study lets us conclude that the inscriptions from the tenth and eleventh centuries are closer to the common speech, while the inscriptions from the fourteenth and fifteenth centuries are more cultured and legitimate. And to finish, the lexicon is very conventional.