This study, based on one of the pioneering studies of József Herman (published in 2000) and using the capabilities and tools of the Computerized Historical Linguistic Database of Latin Inscriptions of the Imperial Age, attempts to describe and analyse the linguistic and dialectological characteristics of Latin in late imperial and early medieval (4-7th century) Italy as evidenced in inscriptions. Limited to the field of phonology, a consonantal and a vocalic phenomenon (the story of the word-final ‑s as well as the e-i and o-u mergers) is the subject of this study which aims to find out whether the late Latin territorial distribution of these changes predicts or anticipates the characteristic territorial differences within the Italian dialects and between the Italian and Sardinian dialects? The study shows that the question posed can be answered in an essentially positive way and that the time of geographically determined occurrence (or non-occurrence) of both discussed phenomena can be given with relative certainty.