The set of surnames Bertarelli, Bertarini, Bertatini and related variants has an anthroponymic origin linked to old names of Germanic root. According to E. Rossoni, they derive from elements such as bertha ("luminous") or bert ("bearer"), very frequent in Gothic, Lombard and Germanic names spread in medieval Italy. These names gave rise to multiple family forms which, over time, became consolidated as surnames.

From the geographical point of view, E. Rossoni notes that Bertarelli is specific to Emilia-Romagna, Bertarini is distributed between Emilia and Lombardy, and Bertatini appears only in the Milan area, possibly as a result of a transcription error of Bertarini. This differentiation reflects the regional evolution of a single onomastic core.

For his part, F. De Laurentiis offers a more synthetic interpretation, considering them derived from Bèrti, which integrates them within the broad family of surnames formed from the name Berto. Taken together, the various interpretations agree in pointing to a common origin of Germanic root, with local developments that gave rise to various variants according to the areas of diffusion.