The authors agree that this surname is of Slavic origin and derives from an Italianization of the name Radoslav.

E. Rossoni places it as typical of Cercemaggiore, in the province of Campobasso, in Molise. S. Vannozzi broadens this information: he notes that the presence in Cercemaggiore, highlighted also by Paolucci, is documented at least from the 16th century, and adds that the oldest records point to S. Croce del Sannio and Morcone, both localities in the province of Benevento, in Campania, which points towards an origin in that zone of southern Italy.