On November 29, H'Hen Niê left Vietnam for Miss Universe 2018 after a year of preparations. Her parents travelled from her home province Dak Lak to Ho Chi Minh City to bid her farewell.

On the very first day of Miss Universe 2018, H'Hen Niê made the acquaintance of many other contestants and showed off a colorful fashion sense. H'Hen Niê changed 3-4 outfits each day.

Thanks to her early arrival, H’Hen quickly completed her introduction photos and video. She also received her Vietnam ribbon. In this photo, H'Hen Niê can be seen wearing a party dress. She asked for designer Do Long’s permission to modify the dress to fit the situation.

H'Hen’s traditional long dress (Áo dài) with brocade patterns received much coverage from Vogue Thailand.

H’Hen and some other contestants visited Chinatown in Bangkok.

On December 4, H’Hen showed off her figure in a sequin cocktail evening dress. She received applause for choosing this instead of a party dress as requested by the organizing board.

The Thai traditional costume show took place on December 5 when she did a short interview with Vogue Thailand. H’Hen admitted that English is not her best area, but she always tries to improve it to communicate with others.

After the show, all pageant contestants were divided into 2 groups. One moved to Pattaya and the other traveled to Krabi. H’Hen Niê went to Pattaya where she visited several relic sites, changed into a bikini and enjoyed the beach.

H'Hen took part in a royal winter parade.

H’Hen was confident in all photo shoots and related activities.

The traditional costume show took place on December 10. A broken hook made her “Vietnamese bread” dress loose its firmness so that H’Hen had to struggled to finish her catwalk. But H’Hen made her name regardless for her professional manner and bright smile.

On December 13, H’Hen, in her ton-sur-ton suit with two pageant contestants from Venezuela and South Africa, participated in a closed-interview with the organizers.

Following the interview, H’Hen participated in a rehearsal for the semifinals. She received recognition in 2 categories: bikini and party outfit. Her twist to spread the dress reminded the audience of Miss Universe 2008 Dayana Mendoza. She was loved and applauded by other contestants. Global Beauties also spoke highly of her performance, saying that H’Hen would move much further ahead in the competition.

Contestants did their best for the final round. H’Hen was assumed to be named in the top 20 and joined the Q&A session. Her faltering answer, however, elicited worry from the audience.

In the final competition on December 17, elation exploded when she was named in the Top 20, Top 10, and finally Top 5. This was the highest position that a Vietnamese contestant has ever achieved at the Miss Universe competition.