The winger has made great strides in his young career, already making over 100 appearances for Sparta Prague and picking up 14 caps for Czech Republic.
There was Premier League interest as West Ham have developed something of a Czech connection in recent years, while former Arsenal star Tomas Rosicky is sporting director at Sparta and gave Hlozek a glowing review.
However, it is Leverkusen who have got their man on a five-year contract.
‘It’s a great thing to have been signed now by one of the best clubs in the Bundesliga,’ Hlozek told bayer04.de. ‘I’ve always watched Leverkusen in recent weeks. The team plays wonderful football. Being a part of this team fills me with great hope and expectation.’
Leverkusen sporting director Simon Rolfes said: ‘Adam is a player who can create a real goal threat as a second striker from a central position or coming in from the wings. His versatility, his power and, above all, his finishing will give our attack more variation.’
Speaking about Hlozek’s development earlier this season, Rosicky claimed the 19-year-old forward is already the best player in the Czech top flight and indicated that the club would be willing to sell this summer.
‘I don’t want to put an absolute burden on such a young boy,’ said Rosicky.
‘He’s led the attack very well for everything he had been up to lately. He is very productive, whether with goals or assists.
I say he’s clearly the best player in the league, knowing it won’t do anything to him because he’s so grounded.
‘I believe that he will score even more goals than now.
‘We don’t want to lose Adam, we are willing to talk about his possible departure in the summer.’