Joe Giudice is hugging his daughters once again, as Teresa and the girls have arrived in Italy to see him. Their eldest daughter, Gia, just shared the family photo on Instagram with the simple caption ... "we're back."

As you know ... after Joe was released from prison, he was in ICE custody for months before going back to his native country, while waiting for his deportation case -- and he's not allowed back for the time being.

Though he's been celebrating with his Italian family since arriving last month, this is the first chance Teresa and the kids have had to come visit him.

All in all ... it's been 3-and-a-half years since their family has all been together on the outside.

As we reported ... Teresa is trying to help Joe obtain an Italian passport so he can travel closer to the U.S. to see them while he awaits the decision on his deportation appeal. Regardless of what happens, Teresa wants to make sure her kids have a relationship with their dad ... even if he can't come back to America.

Looks like this is a good start.