Despite the numerous studies carried out on Latin inscriptions from different parts of the Empire, up to date a complete quantitative analysis on the vowel alternations occurring in Latin inscriptions from Sardinia has not yet been carried out. However, such an investigation could shed light on the dynamics of the emergence of the Sardinian vowel system, where the ‘common romance' mergers of ĭ, ē and ŭ, ō did not take place. Therefore, we conducted a quantitative and qualitative analysis of the graphemic alternations (o) ∼ (U) and (e) ∼ (i) occurring in an epigraphic corpus containing the available Latin inscriptions from Sardinia. The alternations have been examined with reference to four variables: the proportion against standard spellings, the dating of the inscriptions, the position of lexical stress and the amount of other misspellings in the texts examined. The results show a vowel system which seems to foreshadow the Romance development of the Sardinian varieties from early times due to the low number of misspellings. The reconstruction of the sociocultural context of the inscriptions could help us to explain the distribution of the vowel alternations.