gregory
I was there in October. I didn't see a single deck.
The shops I dropped in on were near Calle de la Mandola and Rio Tera de la Mandola. From the street, you'll be able to see a number of decks in this particular tobacconist's window. Inside, he had many decks from European publishers that you simply don't see in the states and in most new age bookstores.
Libreria Miracoli
Via Cannaregio 60-62 - 30131 Venezia
Libreria Il Tempio di Iside
Via San Polo 2659/A - Venezia
#Hi! Since I'm Italian I hope to help who is looking for tarots in my country; just note that I'm from Milan, so I don't know specifically about Venice, but I think that what happens here applies for the majority of the country.
Usually you can find tarots in book shops, both in small/independent ones and in big ones (chains like Mondadori and La Feltrinelli, for example): they can be found in the New Age/Religion area on the shelves and/or on a displayer(?) by LoScarabeo or at the cash desk; just ask the shop assistant if you can't find them!
A more specific place where you can find decks and other related things is the "Libreria Esoterica" (esoteric bookstore), googling I found these two in Venice:
Il Tempio di Iside has also an updated website, so I'm sure it's still open and you can also check out what they have in store!
I hope that I was clear, sorry for my basic english!
I'm back from beautiful magical Venice and found no deck! Not in bookstores, not in tobacco stores. The shopkeepers looked at me as if I was crazy.