Going into the fight, Mike Tyson was the undefeated and undisputed heavyweight champion of the world. He held the WBC, WBA, and IBF titles. Despite the several controversies that marked Tyson's profile at the time, such as his controversial—and, allegedly, abusive—relationship with Robin Givens, the contractual battles between longtime manager Bill Cayton and promoter Don King, and Tyson's departure from longtime trainer Kevin Rooney, Tyson was still dominant in the ring, scoring a 93-second knockout against Carl "The Truth" Williams in his previous fight. Most considered this fight to be a warm-up bout for Tyson before meeting up with then-undefeated number 1 heavyweight contender Evander Holyfield (who was ringside for the fight). Tyson was viewed as such a dominant heavyweight that he was not only viewed as the world's top heavyweight, but often as the number one fighter in the world pound-for-pound (including by Ring Magazine), a rarity for heavyweights.
Buster Douglas was ranked as the #7 heavyweight by Ring Magazine, and had met with mixed success in his professional boxing career up to that point. His previous title fight was against Tony Tucker in 1987, in which he was TKO'd in the 10th round. However, a string of six consecutive wins gave him the opportunity to fight Tyson. In the time leading up to the fight, Douglas faced a number of setbacks, including the death of his mother, Lula Pearl, 23 days before the fight. Additionally, the mother of his son was facing a severe kidney ailment, and he had contracted the flu on the day before the fight.
HBO boxing analysts Larry Merchant and Jim Lampley expected to see "another 90-second annihilation." (When asked by a Japanese customs official how long he expected to be working in Japan, Ed Schuyler of the Associated Press replied, "Oh, about ninety seconds.") Instead of discussing Douglas's chances against Tyson, Merchant and Lampley compared their pets: Tyson had a white pitbull named "Duran" (after his idol Roberto Durán) while Douglas had a beagle named "Shakespeare." Merchant, after saying that "this fight is over before it begins or soon thereafter" and describing Douglas as "just another frozen tuna" from the Tokyo fish market, opined that "any prizefighter with a dog named Shakespeare can be all-bad." In an interview given to HBO prior to the fight, Douglas told reporters that his favorite Shakespeare play was the romantic tragedy Romeo and Juliet. Lampley suggested that if Tyson were asked the same question (assuming he had read Shakespeare), he would chose something more bloody and violent, such as Henry the Fifth or Macbeth.