The event was a joint-promotion pay-per-view, having performers from the Raw, SmackDown, and ECW brands. The main match on the Raw brand was a Triple Threat match for the WWE Championship between Randy Orton, Triple H, and John Cena, which Orton won by pinning Cena. The main event and featured match on the SmackDown brand was Edge versus The Undertaker for the World Heavyweight Championship, which Undertaker won by forcing Edge to submit with the Gogoplata. The main match on the ECW brand was Chavo Guerrero against Kane for the ECW Championship, which Kane won by pinfall after performing a chokeslam. Main matches on the undercard included Floyd Mayweather, Jr. versus The Big Show in a No Disqualification match,<ref name="Mayweather/Show"></ref> an interpromotional Money in the Bank ladder match, and Ric Flair versus Shawn Michaels.
The main feud heading into WrestleMania on the Raw brand was between Randy Orton, John Cena, and Triple H, with the three feuding over the WWE Championship. At the Royal Rumble in January, John Cena won the Royal Rumble match by last eliminating Triple H to become the number one contender to the WWE Championship at WrestleMania XXIV. Instead of challenging Randy Orton for the title at WrestleMania, he wanted to challenge him at No Way Out, the next pay-per-view. At No Way Out, Orton got himself intentionally disqualified by slapping the referee, thus keeping the WWE Championship. Also at No Way Out, Triple H became the new number one contender to the WWE Championship at WrestleMania by winning against five other men in an Elimination Chamber match. The night after on "Raw", after Cena argued that he should have another WWE Championship match, Raw General Manager William Regal said that Cena would face Orton later in the night with the stipulation being if Cena won, he would be added to the WrestleMania match between Triple H and Orton, making it a Triple Threat match. If Orton won, however, the main event would stay as Orton versus Triple H. Cena won the match, pinning Orton after executing an FU. After the match, Triple H, who was the Special Guest referee, executed a Pedigree to both Cena and Orton.
The common feud on the SmackDown brand was between Edge and The Undertaker, with the two battling over the World Heavyweight Championship. On the February 29 version of "SmackDown", Assistant General Manager Theodore Long said that at No Way Out, an Elimination Chamber match would be held to find out who was the number one contender to the World Heavyweight Championship at WrestleMania. Undertaker won the match, last eliminating Batista after executing a Tombstone piledriver.
At No Way Out, The Big Show made a surprise return to the company. In his return promo, Big Show threatened to give Rey Mysterio a Chokeslam. Professional boxer Floyd Mayweather, Jr., who was in attendance and a close friend of Mysterio's, came to his aid and confronted Big Show. Big Show then got on his knees to allow Mayweather to punch him, which Mayweather did, by hitting him with many different punches, which caused Big Show to bleed from the nose and mouth. The next night on "Raw", the Big Show challenged Mayweather to a match, which Mayweather accepted.
On the February 25, 2008 edition of "Raw", 2008 WWE Hall of Fame Inductee Ric Flair challenged Shawn Michaels to a match at WrestleMania, which the latter accepted after some reluctance, knowing that Flair's career will be on the line. Flair also said that "it would be an honor for him to retire at the hands of Shawn Michaels."
Also, on the February 25, 2008 edition of "Raw", the General Manager William Regal was "sent a letter" by the SmackDown General Manager Vickie Guerrero, issuing a challenge to him for an interpromotional "Raw vs. SmackDown" match at WrestleMania XXIV, with each brand choosing one superstar to represent it. Regal accepted and chose Umaga to represent Raw at WrestleMania XXIV. On the February 29 version of "SmackDown", Batista was chosen as the SmackDown representative by Vickie Guerrero against Umaga at WrestleMania XXIV.
On February 18, 2008 WWE said using its website that the fourth annual Money in the Bank ladder match would take place at WrestleMania XXIV, with superstars competing from Raw, SmackDown and ECW. The winner will get a contract to challenge for any of the three WWE World Championships (the WWE Championship of Raw, the World Heavyweight Championship of SmackDown, or the ECW Championship) at any time and any place over a one-year period. Qualifying matches were done to find out who were the participants in the match. Jeff Hardy was at first supposed to be a part of the Money in the Bank ladder match, but was excluded from the event due to his suspension. WWE decided not to fill his spot with another superstar, making this year's Money in the Bank ladder match the first year to only have 7 participants.
On the March 11, 2008 version of "ECW", ECW General Manager Armando Estrada announced a twenty-four-man battle royal at WrestleMania XXIV with the winner going on to face ECW Champion Chavo Guerrero for the ECW Championship following the battle royal. The first announced participant was The Great Khali. WrestleMania XXIV marks the first WrestleMania in which the ECW Championship will be defended. Big Daddy V was at first scheduled to take part in this match, but was removed for unknown reasons. Stevie Richards would also replace Matt Striker, for unknown reasons as well.
Before the show was first shown live on pay-per-view, Kane won a 24-man Interpromotional Battle Royal to win an ECW Championship match against Chavo Guerrero later that night. The event officially began with John Legend singing a rendition of ""America the Beautiful"." The first match that was shown live on pay-per-view was a Belfast Brawl between Finlay and John "Bradshaw" Layfield. Finlay was accompanied to the ring by his returning "son" Hornswoggle, who was injured at the hands of JBL a few weeks ago on "Raw".
The next match of the evening was the fourth-yearly Money in the Bank ladder match, featuring Chris Jericho, Mr. Kennedy and Carlito from the Raw brand; CM Punk, Shelton Benjamin and John Morrison from the ECW brand; and Montel Vontavious Porter (MVP) from the SmackDown brand. The match featured many dangerous spots. Early in the match, Morrison climbed a turnbuckle and performed a moonsault on others outside while holding a ladder against his chest. Then, at one point, when Mr. Kennedy and Morrison were battling on top of a ladder, Benjamin climbed another ladder placed adjacent to the first one, and performed a flip powerbomb on Kennedy, who in turn superplexed Morrison from the top of the ladder. After sometime, Kennedy delivered his Green Bay Plunge to Punk onto a ladder. Later, Carlito and Kennedy flipped Benjamin off a ladder, sending him crashing through another ladder set-up between the barricade and the ring apron. Jericho also performed his Walls of Jericho on Morrison on top of a ladder. Kennedy delivered his Mic Check to Punk off a ladder. Quickly afterwards, Carlito hit the Backstabber to Jericho from a ladder. When MVP was close of finding the contract briefcase, Matt Hardy returned to action through the crowd, entered the ring and delivered the Twist of Fate to MVP off the ladder. As soon as Morrison started to climb a ladder, see-sawing with another ladder, Jericho flipped the other one and Morrison landed on the ring-ropes groin-first. In the end, Jericho and Punk fought each other on a ladder, but Punk trapped Jericho's one leg in the ladder's steps and himself retrieved the contract briefcase to win the match.