Jimmy and Johnny signed with Vincent J. McMahon's World Wide Wrestling Federation (WWWF) in May 1974 and debuted there around that same time. Their biggest success as a tag team came when they defeated Tony Garea and Dean Ho to win the WWWF World Tag Team Championship on 8 May 1974 edition of All Star Wrestling. The Valiants quickly became a dominant heel tag team as they went on to successfully defend their titles throughout the entire year. They held and defended the titles for over a year before losing them to Dominic DeNucci and Victor Rivera on 13 May 1975. This made The Valiant Brothers, the longest reigning champions of their era with a reign of 370 days before the record was broken, fourteen years later by Demolition (Ax and Smash), who reigned as tag team champions for 470 days. After losing the titles, The Valiants battled against the likes of Tony Garea, Dean Ho, Chief Jay Strongbow and Haystacks Calhoun. In 1976, Jimmy and Johnny left WWWF.
In 1978, Valiant Brothers returned to WWWF but Jimmy retired and was replaced by "brother" Jerry Valiant. Jerry and Johnny began wrestling in the tag team division while Jimmy became their manager. In March 1979, the promotion was renamed World Wrestling Federation, dropping 'Wide' from the name. On 24 March 1979 edition of Championship Wrestling, Jerry and Johnny defeated Larry Zbyzsko and Tony Garea to win the WWF Tag Team Championship. This second version of Valiant Brothers was also successful but Jerry could not achieve the popularity which Jimmy had achieved. Jerry and Johnny lost the titles to Ivan Putski and Tito Santana on 22 October. After unsuccessful attempts in winning back the titles from Putski and Santana, The Valiant Brothers broke up in the new year 1980, putting an end to the team.
Jimmy and Johnny were inducted into the 1996 Hall of Fame by Owen Hart and British Bulldog.