Despite having the option to become an unrestricted free agent following the 2010–11 season, Giordano opted to remain in Calgary and signed a five-year, $20 million contract extension with the Flames on October 29, 2010. He led the team's defencemen in scoring and set another career high with 43 points in 82 games. Giordano missed several weeks of the 2011–12 season after suffering a torn hamstring. The injury caused Giordano, who was named an alternate captain prior to the season's start, to miss 21 games. He finished with 27 points in 61 games, then scored 15 points in 47 games in the lockout-shortened 2012–13 season.