Mark Donohue, who qualified in the middle of the front row, took the lead at the start of the race and led the first 50 laps.

He and Joe Leonard swapped the lead several times during the middle portion of the race, but Unser led for the final 83 laps, giving him a win for the second year in a row.

The 1971 Indy 500 was part of the newly re-organized USAC Marlboro Championship Trail, in which dirt tracks were separated from the paved ovals and road courses.

The city of Indianapolis celebrated its Sesquicentennial in 1971, and the occasion was reflected on the bronze and silver pit badges for the month of May.

The Uniform Monday Holiday Act had taken effect in 1971, and the Speedway moved the race off of its original traditional fixed date of May 30.

For 1971, the traditional Carburetion Day practice, held on Wednesday May 26, was officially open to the public for the first time.

As had been done in previous years, a blind draw would be held to determine the order of qualifying on pole day.

However, starting in 1971, all drivers/cars in the original qualifying draw order would be allowed the opportunity to make at least one attempt in the pole round regardless if rain halted the session and pushed it off to another day.

During practice, McLaren arrived at the track with the new M16 chassis, drawing attention and some controversy due to presence of a large rear wing affixed to the engine cover.

[11] After inspection, officials ultimately approved the device, as McLaren argued it was part of the engine cover.

Mark Donohue in the Penske-owned McLaren had broken the 180 mph barrier during practice on Thursday, establishing himself as the favorite for the pole.

Later in the day, Peter Revson, driving a works McLaren, bumped Donohue from the pole with a four-lap average of 178.696 mph.

Donohue reportedly suffered handling problems with his car during his run, purportedly as a result of his crew refusing to dial it in as he requested.

[4] Jim Hurtubise once again tried to qualify his front-engined roadster, but on his second lap, hit the outside wall at the head of the main stretch.

Four local Indianapolis-area Dodge dealers, spearheaded by Eldon Palmer, stepped up to supply the fleet of pace cars.

[18] During the parade and pace lap, Tony Hulman, ABC broadcaster Chris Schenkel, and John Glenn served as passengers in the car.

Palmer continued to accelerate, under the impression that he was required to cross the start/finish line in the pit area prior to, or at the same time, as the race cars doing so out on the track.

Moving upwards of perhaps 125 miles per hour (201 km/h), Palmer realized he was going too fast, and rather than perilously veering back on to the racing surface, he braked heavily and lost control.

[18][20] Furthermore, Palmer's attorney added that a security guard running out of the way effectively blocked the exit to the pits.

[22] Tony Hulman suffered a sprained ankle, and a shaken Schenkel sat out the remainder of the ABC broadcast.

Despite the pace car crash near the exit of the pits, the green light came on, and the race continued underway.

The only injury received by Kenyon was a small cut on his shin from the dash board being pushed down onto his legs.

Rick Muther spun in the oil, his car veered to the inside wall, then bounced across the track, hitting Hobbs, and lifting up on two wheels.

After a series of pit stops by the leaders under the yellow, the green eventually came back out with Al Unser leading.

In a departure from previous years, Sid Collins decided to eliminate booth interviews with celebrities during the race.

In addition, Luke Walton interviewed Evel Knievel in the pit area during the early stages of the race.

Among the notable appearances, was David Letterman, at the time employed by then-ABC Indianapolis affiliate WLWI, who served as a roving turn reporter.

Chris Schenkel began what would be a decade-long tenure as host, while Jim McKay anchored the broadcast as play-by-play announcer.