The Polish striker was officially unveiled as a Bayern player on Wednesday after leaving Dortmund on a free transfer.
Lewandowski believes that he is more likely to win titles at the Allianz Arena than he if he were to stay at the Westfalenstadion.
"It was time to take the next step," the 25-year-old is quoted as saying by Goal.com. "I knew that Bayern Munich are of the level where I can be an even better player and win even more titles."
Lewandowski scored 26 goals in 42 appearances for Dortmund last season.