Guerrero's contract with WCW was one of the twenty-five contracts that were included in WCW's sale to the World Wrestling Federation (WWF). Like most of the wrestling talent that came over with WCW, Guerrero wrestled as a heel under the WCW banner as his WWF debut was as part of The Alliance, a group of WCW and ECW employees who had, in storyline, invaded WWF after their promotion was bought out. On April 13, 2002, Guerrero faced Billy Kidman on an episode of WWF Metal for the Cruiserweight Championship and lost the match via pinfall. Guerrero spent time as an undercard wrestler in the company, which was soon rebranded World Wrestling Entertainment, wrestling for the WWE Cruiserweight Championship on numerous occasions.
