On 18 August 2009, Bender signed a three-year contract with Bayer Leverkusen.
He played his first match in the Bundesliga coming off the bench on Matchday 6 and was used as a substitute in most of 20 games he played during his first season in Bayer Leverkusen.
He scored his first goal in the Bundesliga against Eintracht Frankfurt on 16 September, an eventual 4–0 win.
In the following season, his position in the defensive midfield remained competitive and he was often second choice, but he played 27 matches and scored three goals.
In the 2011–12 season, he was a regular player and played most of the games over the full season, only interrupted by a forced break for a muscle bundle crack injury in the spring of 2012.
On 21 March 2012, Bender signed a new contract with Leverkusen to 2018.
In the 2012–13 Bundesliga season, he played 33 games, scored 3 goals and made 6 assists.
On 31 October 2013, he extended his contract with Leverkusen until 2019.

In the 2013–14 season, he played 29 games and scored three goals in the Bundesliga, despite being injured for the most of September and October and again in the spring of 2014.
In the 2014–2015 season, he's comeback to field and played 26 games in Bundesliga, he's made only one goal in this season against SC Paderborn 07.
In UEFA Champions League he helped Leverkusen to finished runner-up in Phase Group behind AS Monaco but later lost by Atlético Madrid on Round of 16.
For season 2015/16 coach Roger Schmidt appointed him as the new team captain in place of Simon Rolfes, who had ended his career after the end of the preseason.
This season is a struggle for him, after had long time injury in October 2015 until March 2016, and he's only got 10 appearances in Bundesliga and made a pair appearances in Champions League.
On 18 August 2009, Bender signed a three-year contract with Bayer Leverkusen. He played his first match in the Bundesliga coming off the bench on Matchday 6 and was used as a substitute in most of 20 games he played during his first season in Bayer Leverkusen. He scored his first goal in the Bundesliga against Eintracht Frankfurt on 16 September, an eventual 4–0 win. In the following season, his position in the defensive midfield remained competitive and he was often second choice, but he played 27 matches and scored three goals. In the 2011–12 season, he was a regular player and played most of the games over the full season, only interrupted by a forced break for a muscle bundle crack injury in the spring of 2012. On 21 March 2012, Bender signed a new contract with Leverkusen to 2018. In the 2012–13 Bundesliga season, he played 33 games, scored 3 goals and made 6 assists. On 31 October 2013, he extended his contract with Leverkusen until 2019. 
In the 2013–14 season, he played 29 games and scored three goals in the Bundesliga, despite being injured for the most of September and October and again in the spring of 2014. In the 2014–2015 season, he's comeback to field and played 26 games in Bundesliga, he's made only one goal in this season against SC Paderborn 07. In UEFA Champions League he helped Leverkusen to finished runner-up in Phase Group behind AS Monaco but later lost by Atlético Madrid on Round of 16. For season 2015/16 coach Roger Schmidt appointed him as the new team captain in place of Simon Rolfes, who had ended his career after the end of the preseason. This season is a struggle for him, after had long time injury in October 2015 until March 2016, and he's only got 10 appearances in Bundesliga and made a pair appearances in Champions League.
Lars Bender