It was the thirteenth Indy 500 sanctioned by the Indy Racing League, and served as the showcase event of the 2008 IndyCar Series in DIRECTV HD season. It was the fifth round of the 2008 IndyCar Series season. It was the first Indy 500 after the open wheel "unification" took place, and it featured a full complement of entries of IndyCar Series regulars, as well as former Champ Car teams.

It was the first Indy 500 where all entries utilized the Dallara IR5 chassis after Phil Giebler failed to qualify with Panoz chassis - effectively ushering in a four-year "spec" era. In addition, all full-time entries began utilizing semi-automatic paddle shifters in 2008. Paddle shifters for part-time Indy 500-only entries were optional.IndyCar Series practice began May 4. Time trials took place over the two weekends prior to the race (May 10–11 and May 17–18). The final practice was held Friday May 23.

* Includes days where track activity
was significantly limited due to rain

ROP — denotes Rookie Orientation Program

Comm. Day — denotes 500 Festival Community Day

Julianne Hough, who partnered with two-time Indy 500 winner Hélio Castroneves to win Dancing with the Stars, sang the national anthem.Jim Nabors returned to sing "Back Home Again in Indiana" after an illness prevented him from doing so in 2007.1992 Winter Olympics women's figure skating gold medalist Kristi Yamaguchi, the season six winner of Dancing with the Stars, served as the honorary starter and wave the green flag.

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