Fourteen entries competed in the national final on 13 February 2021 and "Tick-Tock" performed by Albina was selected as the winner following the combination of votes from ten regional juries and a public televote.

Performing during the show in position 10, "Tick-Tock" was not announced among the top 10 entries of the first semi-final and therefore did not qualify to compete in the final.

Since 2018, the Croatian entries failed to qualify from the semi-finals; the last time Croatia competed in the final was in 2017 with the song "My Friend" performed by Jacques Houdek.

[3] Between 1993 and 2011, HRT organised the national final Dora in order to select the Croatian entry for the Eurovision Song Contest.

The competition consisted of fourteen entries competing in one final on 13 February 2021 at the Marino Cvetković Sports Hall in Opatija, hosted by Daniela Trbović, Barbara Kolar, Jelena Lešić and Doris Pinčić Rogoznica.

[7] On 26 October 2020, HRT opened a submission period where artists and composers were able to submit their entries to the broadcaster with the deadline on 10 December 2020.

A five-member expert committee consisting of Andrej Babić (HGU, HDS), Hrvoje Prskalo (HDS), Matija Cvek (HGU), Monika Lelas (HRT) and Uršula Tolj (HRT) reviewed the received submissions and selected fourteen artists and songs for the competition.

The winner, "Tick-Tock" performed by Albina, was determined by a 50/50 combination of votes from ten regional juries and a public televote.

[14] After the final, Nina Kraljić alleged that there were problems with her rehearsals, where she had to listen to Albina's song in her in-ear headphones instead of her own.

[16] The next day, the family of another contestant, Bernarda Brunović, also alleged that they received information from Croatian Head of Delegation Uršula Tolj that they could not win because they were on a "blacklist".

[25][28] Albina was joined on stage by four dancers performing choreography with the singer: Devin Juraj, Luciano Plazibat, Marko Marić and Stjepan Cutvarić.

[29] At the end of the show, Croatia was not announced among the top 10 entries in the first semi-final and therefore failed to qualify to compete in the final.

[30] Jury members may only take part in panel once every three years, and are obliged to confirm that they are not connected to any of the participating acts in a way that would impact their ability to vote impartially.