The defender had been very close to Atletico Madrid, but yesterday the German club landed him in a loan deal.
Molinaro will spent the next six months on loan in Stuttgart and is already on German soil.
"I like the Bundesliga," he told Sky Italia television. "I am finally here, after a long journey, at last."
He comes to reinforce a struggling Stuttgart side that is currently third from bottom with just 16 points.
"The team is not in a position it usually holds in the table and decidedly deserves better."