BVB signed Immobile from Juventus and Torino after losing Robert Lewandowski to Bayern on a free transfer and Trapattoni has little doubt that his compatriot will succeed at Signal Iduna Park.
"Lewandowski is Lewandowski and Immobile is Immobile. Ciro is a very intelligent player, though. He can play in the middle, but on the left or right as well," the veteran boss told Bild.
"Ciro is a godsend for [Jurgen] Klopp. He would have been good enough for Bayern as well. Ciro is only 24 years old and still has room for improvement.
"He is a clinical finisher. He scored 22 goals in Italy and will get plenty of goals in the Bundesliga as well."
Trapattoni also feels that Immobile will become a stronger player in Germany while working under one of the finest coaches in the game.
"The transfer to Dortmund will also benefit Ciro," he enthused. "He now gets the chance to work with one of the best coaches in the world.
"I am very impressed with what Klopp has achieved with Dortmund and how he has helped young players develop. It's good fun to see him at work."