In 1979, Sheik joined the World Wrestling Federation (WWF) where he made his debut in 1979 and won the first-ever Battle Royal in Madison Square Garden, New York City. This earned him a title shot at then-champion Bob Backlund, who pinned him later that night in a 30-minute battle. He later feuded with Chief Jay Strongbow and Bruno Sammartino before leaving in 1980.
The Iron Sheik returned to the WWF in 1983 and challenged Bob Backlund for WWF World Heavyweight Championship again. Backlund accepted, and on the December 24 episode of All- American Wrestling, also accepted Sheik's weekly Persian club challenge. He was successful in his third attempt to swing the clubs, and the Sheik immediately attacked him from behind, injuring his neck. In the December 26 title bout at Madison Square Garden, Backlund attempted to roll Sheik into a bridge pin, but this aggravated his weakened neck. Sheik capitalized by applying his Camel Clutch chinlock finisher. Backlund didn't submit, but his concerned manager Arnold Skaaland threw in the towel and forfeited the championship.
The Iron Sheik faced Backlund in a rematch indecisively at house shows and primarily defended the title against Chief Jay Strongbow, as well as Pat Patterson and Salvatore Bellomo. On national TV, he defeated only jobbers, but wrestled Tito Santana in Philadelphia on January 21, 1984.
Two days later, at Madison Square Garden, The Iron Sheik was scheduled to rematch Backlund, who was replaced by Hulk Hogan. Five minutes in, Sheik had Hogan locked in the Camel Clutch. Hogan powered to his feet with Sheik still on his back, rammed him backwards into the turnbuckles and hit his Atomic Legdrop for the pin and the championship. This moment is generally considered the beginning of "Hulkamania".
He then bitterly feuded with Sgt. Slaughter, winning a few matches by disqualification, but losing the rest by pinfall, including a "Boot Camp Rules" match.
As a tag team partner with Nikolai Volkoff, and under the management of "Classy" Freddie Blassie, the newly dubbed "Foreign Legion" won the WWF Tag Team Championship from The U.S. Express (Barry Windham and Mike Rotundo) at the first WrestleMania at Madison Square Garden when he knocked out Windham from behind with Blassie's cane. Part of the pair's regular entrance consisted of waving the flags of Iran and the Soviet Union, then demanding that the crowd be quiet and "show respect" while Volkoff sang a throaty version of the Soviet national anthem, a demand that usually only attracted boos from the usually pro-American crowds. Sheik then usually grabbed the mic and said "Iran number 1, Russia number 1, USA (followed by a simulated spitting act)." It was all designed (very successfully) to get major heat from the crowd.
During 1986, Fred Blassie was beginning to wind down his career and as part of the story line, eventually sold his wrestlers contracts to new WWF manager Slick before retiring. This included the Sheik and Nikolai Volkoff who would now be managed by the "Doctor of Style". The Sheik was a participant in the 20-man invitational battle royal in the Chicago portion of WrestleMania 2 which saw fourteen WWF superstars in the ring with six National Football League (NFL) players. The Sheik was the thirteenth participant eliminated, at 5:22 by Bruno Sammartino.
At WrestleMania III, he and Volkoff defeated The Killer Bees (Jim Brunzell and B. Brian Blair) in a tag team match. The Iron Sheik left the WWF soon after.
On February 18, 1988, The Iron Sheik returned to the WWF and defeated SD Jones at a house show at the Meadowlands Arena in East Rutherford, New Jersey. Sheik continued to wrestle on house shows in February and March, facing Lanny Poffo, Ken Patera, and Bam Bam Bigelow. He would not appear on television until July 30, when he defeated Scott Casey in a match that aired on Prime Time Wrestling. Sheik continued to wrestle that summer, facing Casey in rematches as well as Richard Charland and The Red Rooster. Iron Sheik had also cut promos to challenge then-World Champion "Macho Man" Randy Savage, but nothing came of it. Ultimately the return was short-lived and Sheik departed once more.
In 1987, The Iron Sheik competed in Dallas' World Class Championship Wrestling (WCCW) where he feuded with Matt Borne. He stayed with that organization for only a few months, followed by brief stints with the AWA, where he attacked Sgt. Slaughter during a match.
On February 25, 1989, the Iron Sheik made a surprise appearance at a WCW taping in Atlanta, Georgia and immediately challenged Ricky Steamboat. On April 11, he challenged Sting at a television taping to a Persian clubs swinging competition. On the April 29 episode the competition ensued, which Sting admitted that Sheik had won, leading to a match between the two at Music City Showdown. On May 7 the two faced off, and Sheik was defeated by TV Champion Sting.
In August 1989, he would form a brief alliance with Ron Simmons, appearing in his corner during a match with Jon Brewer. He would appear later that month in the corner of Simmons and The Cuban Assassin in a victory over Tommy Rich and Eddie Gilbert. On August 26, Simmons and Sheik were guests of Paul E. Dangerously's "Danger Zone", where he admitted that he was now training Simmons and was looking for a tag team partner for him. The angle was eventually dropped and Simmons went on to team with Butch Reed as Doom, while Sheik finished his initial WCW tenure in house show matches against Norman in January 1990.
The Iron Sheik would return after a seven-month absence. On July 7 at The Great American Bash, he faced Mike Rotunda in a losing effort in his first match back. He wrestled Brian Pillman, Tom Zenk, Terry Taylor, Brad Armstrong, and Big Van Vader on the house show circuit through the fall and winter of 1990. His final match was against the Junkyard Dog on January 26, 1991 in Columbia, South Carolina, after which he left the company.
He returned to the WWF again on March 11, 1991, making his re-debut on Wrestling Challenge as Colonel Mustafa, and was aligned with former enemy Sgt. Slaughter. Along with Iraqi General Adnan, Slaughter and Mustafa were portrayed as Iraqi sympathizers during the Gulf War and feuded with Hulk Hogan and the Ultimate Warrior. Following Slaughter's face turn after SummerSlam 1991, Mustafa remained aligned with Adnan. He dropped to a lower midcard position, primarily losing matches against faces such as Slaughter, Tito Santana and Tatanka. Mustafa would challenge for the WWF World Championship during the star-studded 1992 Royal Rumble match. Shortly thereafter, Adnan left the WWF and Mustafa would be without a manager for his final four months with the company, His final match was at a Superstars taping on May 19, 1992 where he defeated Reno Riggins, after which he left the promotion again.
In late 1996, the Sheik teamed with his old nemesis Bob Backlund to manage WWF wrestler The Sultan, who had a Middle Eastern gimmick. He would manage Sultan until December 1997. He also for a time during the summer of 1997 co-managed Tiger Ali Singh (with Ali's father, Tiger Jeet Singh). By the year's end he was released.
On April 1, 2001, at WrestleMania X-Seven, The Iron Sheik won the Gimmick Battle Royal, a match between other popular or outlandish wrestlers from the 1980's and 1990's. Rather than being booed for winning, the villainous Sheik was cheered as a fan favorite. He eliminated Hillbilly Jim to win the Battle Royal and was immediately attacked by former rival/partner Sgt. Slaughter who put him in his Cobra clutch.
In 2005, before WrestleMania 21 in Los Angeles, The Iron Sheik was inducted into the WWE Hall of Fame by his long-time rival and former partner, Sgt. Slaughter. On the June 11, 2007 episode of Raw, he, along with Jimmy Snuka, appeared in a taped segment showing their appreciation of WWE owner Vince McMahon. On the June 18 episode of Raw, he approached McMahon's executive assistant Jonathan Coachman about having his own interview show on Raw. Coach replied saying, "I like the idea and I will really take some time to consider it." On August 13, he appeared on an episode of Raw held at Madison Square Garden for a WWE version of American Idol. Sheik came out with Nikolai Volkoff while Volkoff sang the Soviet anthem. The March 10, 2008 edition of Raw featured rematches from previous WrestleManias. Iron Sheik appeared with Nikolai Volkoff to face off against the U.S. Express in a rematch from the first WrestleMania. Before the bout could begin, they were interrupted by Jillian Hall.
On October 2, 2009, on the 10th anniversary of SmackDown, he appeared backstage arguing with Sgt. Slaughter, choking on a shrimp, then helped by Hurricane Helms.
He made an appearance on Raw on November 16, 2009 in the opening of the show, with Rowdy Roddy Piper and Luis Guzmán.
On the November 15, 2010 edition of Raw, as part of the Old School theme, Iron Sheik appeared with Nikolai Volkoff, singing the Soviet national anthem before being interrupted by Santino Marella and Vladimir Kozlov, the latter of whom then sung a duet with Volkoff of the Russian National anthem. He then proceeded to rant on Hulk Hogan until his microphone was cut off.
Sheik passed away on June 7, 2023.