The 19-year-old Cardinale auditioned in New Orleans with Karla Bonoff’s “Standing Right Next to Me”. In the Hollywood rounds, she sang “Ain’t No Mountain High Enough,” “I Can’t Help Myself (Sugar Pie Honey Bunch),” (along with semi-finalist Melinda Lira and fellow finalist Jessica Sierra) and “The Woman in Me (Needs the Man in You).” She went on to the three-round semi-finals composed of the top 12 women and top 12 men. There she sang “Standing Right Next to Me,” “I Try to Think About Elvis,” and “I Don’t Want to Miss a Thing.” She made it to the top 12 alongside 11 others. On March 16, 2005, she was voted off, after her performance of “Knock on Wood” during the 1960s-theme music week. Cardinale later freely admitted that she did not enjoy singing “Knock on Wood” and tried everything she could to get out of recording it for the subsequent American Idol compilation album, but ultimately had to accept it and record it. Cardinale was also included on the AI season four’s charity single to benefit the Red Cross Tsunami Relief Fund, “When You Tell Me That You Love Me,” along with the other 11 finalists.
Cardinale appeared at Ponchatoula’s Strawberry Festival shortly after her elimination; she thanked her hometown for their contributions that helped her place twelfth out of hundreds of thousands of auditions. However, her contract with 19 Entertainment prevented her from singing at the fair, so she played the drums instead. A year later at the festival, on April 8, 2006, Cardinale put on an hour-long show of cover tunes and two original songs. However, she was visibly disturbed after spotting two women at the festival who sported signs with derogatory statements. However, the experience toughened her up to criticism and helped rally her fans to her support. Cardinale was quoted as saying, “I did deal with Simon Cowell for six weeks, and if I can deal with him, I can deal with anybody… This whole town has my name painted across it, I can’t worry about the negatives, I chose this career!”