García was hired by the World Wrestling Federation as a ring announcer in 1999. She made her debut on the August 23, 1999, episode of Raw is War in Ames, IA. She was involved in her first angle on the September 13 episode of Raw is War, when Jeff Jarrett applied a figure four leglock to her after she angered him by announcing his loss by disqualification to Luna Vachon.
Garcia's second angle occurred on the December 13, 1999, episode of RAW. Lilian introduced Miss Kitty for a Women's Championship chocolate pudding pool match. After Lilian announced her, Miss Kitty grabbed the mic and informed Lilian that she was now to be known as "The Kat". Her opponent, Tori, came out for their match and right after the two women began, X-Pac came poolside in a skin diving suit complete with snorkel, flippers, and goggles. As he was adjusting his goggles Tori jumped on his back causing both of them to fall into the pool with X-Pac landing up on top of Tori, giving Miss Kitty an easy pinfall. Lilian announced the winner as "Miss Kitty", which infuriated The Kat, who threw Lilian into the pool of pudding.
García sang in the WWF for the first time on February 14, 2000, at a house show, and began singing "The Star-Spangled Banner" at television tapings later that month. Her first televised performance was on April 2, 2000, where she opened WrestleMania 2000. Following the September 11 attacks, Garcia sang "The Star-Spangled Banner" on the September 13, 2001, episode of Smackdown!, receiving a standing ovation.
In mid-2002, García briefly "feuded" with rival announcer Howard Finkel after Finkel left her to be decimated by 3-Minute Warning, culminating in an "evening gown versus tuxedo match" that Garcia won with the assistance of Stacy Keibler and Trish Stratus.
In June 2005, García began an on-screen romance with wrestler Viscera. The angle saw García propose to Viscera, stating that she wanted to marry him during the Vengeance pay-per-view on June 26. The angle ended at Vengeance when Viscera rejected Garcia in favor of The Godfather's "Hos". The angle was briefly resurrected eleven months later when Viscera proposed to Garcia on the May 22, 2006, episode of Raw, but was interrupted by Umaga before receiving an answer.
On the June 5, 2006, episode of Raw, Garcia (legitimately) suffered a sprained wrist when wrestler Charlie Haas inadvertently knocked her to the ground as she stood on the ring apron. One week later, the accident was metamorphosed into a storyline, with Haas incurring the wrath of Viscera. The storyline ended on the July 10, 2006, episode of Raw, when Viscera "accidentally" performed a Samoan drop on Garcia while confronting Haas. Garcia was removed from television for several weeks in order to sell the Samoan drop.
She returned to announcing on the July 2, 2007, episode of Raw after taking time off to recover from a skiing injury in which she tore the ACL in her right knee. She was not fully recovered as was evident from her only announcing the first two matches from the ring and the rest from the floor.
Lilian then started a feud with Jillian Hall, who claimed to be a better singer than Lilian. The next week, she competed in WWE Idol, a parody of American Idol, in which she sang "New York, New York" by Frank Sinatra before being interrupted by Santino Marella.
In addition to announcing on Raw and Raw pay-per-view matches, Garcia would also announce on WWE Superstars making her first appearance on April 23, 2009.
On the September 21, 2009, episode of Raw from Little Rock, Arkansas, Jerry Lawler announced to the live audience that it was Garcia's final night with WWE. Garcia then made an emotional speech in the ring, thanking the fans and all of her colleagues. The final match she announced live featured Randy Orton, Chris Jericho and Big Show taking on the team of John Cena, Montel Vontavious Porter and Mark Henry, although a match between Primo and Chris Masters was taped earlier that evening and aired three days later on WWE Superstars, marking her final television appearance.
Garcia made a special appearance before the Madison Square Garden audience on November 16, 2009, singing The Star-Spangled Banner prior to the evening's Raw telecast. Garcia filled in for Raw ring announcer Justin Roberts on April 19, 2010. Garcia attended WWE's SummerSlam Kickoff Party in Hollywood, on August 14, 2010.
On December 5, it was announced on WWE.com, that Garcia would be returning to ring announcing full-time, appearing on SmackDown!. She returned at the December 6 tapings of the show. She also serves as the ring announcer for Main Event and PPVs.
Garcia suffered accidents prior to Smackdown tapings in 2012. While heading to the ring prior to the March 13 taping in Columbus, Ohio, the strap on her left shoe broke. One month later, during the April 17 taping in London, England, she tripped over pyrotechnic equipment on the top of the stage and fell down on the ramp, landing on her knees. At the TLC pay per view she announced that the bell would toll 26 times for the victims of the Sandy Hook shootings. On the April 19th 2013 episode of SmackDown she was involved in a segment with Fandango, learning dance steps from Fandango and insulted by him. On the June 6th 2014 episode of SmackDown, she was involved in a confrontation with Alicia Fox. After Alicia had lost her match to Natalya, Alicia went on a violent rampage as she had been doing previous weeks. Alicia pranced around ringside threatening everyone in sight. When she came across to Lilian she lured her into a corner and began to scream at her and asked why she rang the bell. Lilian then told Alicia she had no part of it and Alicia backed down. On October 13th, 2014, Justin Roberts was released from WWE after Raw went off the air. The following week on the October 20th episode of Raw, Lilian returned as the ring announcer for the show. In April 2015, Garcia underwent knee surgery, leaving her off television. Lilian returned from knee surgery on May 31st, at the Elimination Chamber pay per view.
On August 1, 2016, Garcia announced that she left WWE to tend with personal issues.