The German team announced on Monday that they have secured the services of the promising Polish striker, who joins the Werkself on a five-year deal for an undisclosed fee
The 18-year-old Polish attacker, who recently debuted for the national team, joins for an undisclosed fee on a deal until 2018 and recently attended B04's 3-0 victory over Hamburg on Saturday.
Milik was overjoyed with the move and revealed that he was impressed with the club's determination to acquire his services.
"I felt Bayer Leverkusen definitely wanted me. They pulled out all the stops to sign me," the striker told the club's official website.
"The match [against Hamburg] confirmed I made the right decision. It was a great experience. The performance on the pitch was outstanding.
"The atmosphere at the stadium was fantastic. As far as I’m concerned, it was a perfect demonstration of what football in Germany should be about."
Leverkusen managing director Wolfgang Holzhauser believes Milik is set to play an important role for the Werkself in the future, and looked forward to seeing him in action.
"Arkadiusz Milik is considered to be possibly the biggest rising star in Poland at the moment," he said. "He has already made it to the Poland squad at the age of 18.
"Our coaching team led by Sascha Lewandowski and Sami Hyypia will take care of his development with us. I’m sure he will be a very valuable addition to the squad."