In 1977, Patera challenged Bruno Sammartino for the WWWF Heavyweight Championship in the World Wide Wrestling Federation. He was one of Sammartino's last challengers before losing the title to Superstar Billy Graham, which ended his second, shorter WWF title reign. When Bob Backlund later won the title, Patera also unsuccessfully challenged him.
At the height of his career, in 1980, he held the Intercontinental Heavyweight Championship.
Patera was an integral part of the Heenan Family in the AWA in 1982, and later in the WWF. While in the AWA, he feuded with Hulk Hogan, Greg Gagne and Jim Brunzell. During Heenan's absence in 1983, caused by a back injury, Patera joined forces with manager Sheik Adnan El-Kaissie and formed a tag team with Jerry Blackwell known as "the Sheiks" (with Patera calling himself "Sheik Lawrence of Arabia"); both men wore Arabian-style garments and feuded with the High Flyers (Greg Gagne and Jim Brunzell) over the AWA World Tag Team Championship, winning the belts in June 1983. Patera and Blackwell later lost the titles to Baron Von Raschke and the Crusher. In the WWF, Patera resumed his feud with Hogan, and also assisted Big John Studd in his feud with André the Giant, helping Studd cut Andre's hair after both had attacked him.
The WWF brought Patera back to the company in the spring of 1987, airing vignettes on WWF television and releasing a Coliseum Video cassette entitled The Ken Patera Story, which chronicled his career and his return. He was in top physical condition at this point, and his appearance had changed, as he wore natural brown hair, rather than his previous bleached blonde look. To ensure he would be accepted as a babyface, he claimed that former manager Bobby Heenan had abandoned him. Patera and Heenan held a debate to air their differences, which turned into a physical confrontation between the two that culminated in Patera swinging Heenan with a belt around his neck, causing Heenan to appear on television with a neck brace for months. Patera then began feuding with the Heenan Family (at the time composed of Paul Orndorff, Harley Race, King Kong Bundy and Hercules). In his first match back at Madison Square Garden, the final match of the night, he defeated the Honky Tonk Man via submission with a bearhug, to a huge ovation.
Shortly after his return, Patera ruptured the bicep tendon in his right arm, which led him to miss some time and re-emerge afterward with a stiff and bulky full-length brace for protection. Within six months, Patera was being defeated by newer, younger talent and found himself floundering in a mid-card tag team with Billy Jack Haynes. The pair would later feud with Demolition after a televised match where Demolition left Haynes, Patera, and Brady Boone (who played Haynes' cousin) beaten and lying in the ring. In his final televised WWF matches in late 1988, he picked up losses to Bad News Brown, Dino Bravo, "Outlaw" Ron Bass, One Man Gang, Greg Valentine, and "Red Rooster" Terry Taylor). His final appearance for the WWF was at the 1988 Survivor Series on November 24, where he was the first member of his team to be eliminated when "Ravishing" Rick Rude pinned him with the Rude Awakening.
Patera returned to the AWA in early 1989 and unsuccessfully challenged the new AWA World Champion Larry Zbyszko for the title. He then teamed with Brad Rheingans as "the Olympians." The team defeated Badd Company for the AWA World Tag Team Championship shortly thereafter, but their reign was brief. Wayne Bloom then challenged Patera to a "car-lifting challenge" in order to get a title shot for him and his partner, Mike Enos. When it was Patera's turn to lift, Enos and manager Johnny Valiant attacked and (kayfabe) injured Patera and Rheingans. This led to the AWA stripping Patera and Rheingans of the titles. Patera continued to feud with Bloom and Enos until he left the AWA.