About 10 robbers were involved in the paramilitary-style operation, Italy's ANSA news agency reported.
They allegedly opened fire with AK-47s, emptied one of the two vans of cash and fled the scene in three cars.
No injuries were reported.
It was initially reported that the thieves made off with more than $13 million, but police said it was actually much less.
"At the moment we are not able to give an exact figure as we don't know it, but 10 million euros [about $13 million] is a totally exaggerated figure," Marco Melatti, the press office chief of Gruppo Battistolli di Vicenza, told ANSA.
"A major haul could be in the area of a few million euros," Melatti said. "What we can say is that there are banks, private institutions and major retail groups among our clients in the area and so the overall haul is the sum of a series of figures collected."