The Turkish international put pen-to-paper on his new contract on Wednesday in the presence of the club's general manager Michael Schade and sporting director Rudi Völler.
"I'm really pleased that we've agreed on this long cooperation," said Toprak, who arrived in Leverkusen in 2011 from Bundesliga rivals SC Freiburg. "Bayer 04 have placed a lot of faith in me in these few years, but that is not the only reason why I feel so happy in Leverkusen. We've got a strong team with which we can achieve our lofty ambitions. That is why it was such an easy decision for me to commit to the club until 2018."
Toprak, 24, has established his place at the heart of the Leverkusen defence, appearing in 14 of their 17 games so far this season. He has also developed an eye for goal, scoring twice in six UEFA Champions League appearances to help Sami Hyypiä's men set up a last-16 tie with Paris Saint-Germain.
"Going to get even better"
Offering him a new deal was therefore only a matter of course for Die Werkself. "We've made a point not only of signing talented players with lots of potential, but also keeping hold of the established players we already have in order to remain competitive at home and abroad," said Schade. "We've managed that already with Stefan Kießling, Lars Bender and Bernd Leno, and Ömer Toprak belongs in this same category."
Völler has also been delighted with Toprak's progress since he arrived with only 38 Bundesliga appearances under his belt. "Particularly last year, Ömer took a huge leap forwards," said the former Germany coach. "He's gained an air of authority and takes on responsibility on the field of play. We regard Ömer as one of the cornerstones of our team and he's going to get even better in years to come."