Originating from Alexandroupoli, she auditioned for The Voice of Greece at the age of sixteen.^[1] Appearing on the eighth of the eight blind auditions, she auditioned with "Let Her Go", originally by Passenger—with two coaches: Michalis Kouinelis and Despina Vandi electing for her to join their teams; from which Kosmidou selected Michalis Kouinelis.^[2] During the battles, Kosmidou sung "I Was Made for Lovin' You" against Christina Miliou–with Michalis crowning her as the winner.^[3] In the second live show, she performed "Big in Japan" and was saved by the public.^[4] In the third live show, she performed "Little Talks" and was saved by the public along with Uri Melikov.^[5] In the fourth live show, she performed "Royals" and was for the first time in the bottom two along with Panayiotis Vintzilaios–with Michalis selecting her to proceed to the semi-final.^[6] In the semi-final, she performed "This Is the Life" for her solo performance and "Poison" for her duet with the band Melisses.^[7] Kosmidou proceeded to the final after getting 53 points from her coach and 57 points from the public.^[7] Her song "So Cruel" was available on iTunes the day after the semi-final, on May 3, 2014.^[8] In the final she performed her original song "So Cruel" and a duet with her coach with the song "Prin Se Gnoriso".^[9] As she advanced to the second round along with Kiriakou and Kintatos, she performed "Let Her Go", the song she performed during the blind auditions.^[9] Kosmidou finished as joint runner-up with Kintatos.

During her appearance in the show, Kosmidou received a proposition from Sakis Rouvas to appear with him in his upcoming concert in Athens.^[10] However, she had to turn down the proposition as according to the rules of the show the contestants could not appear in any other concerts.^[11]