Nunes made her debut in December 2013 at Invicta FC against Muna Holland and subsequently took home the title of Knock out of the night Bonus.
She made her UFC debut at UFC 56 on November 8, 2014, against Juliana Lima but lost the fight by unanimous decision. Due to illness at UFC 187, she was withdrawn from the event entirely on May 23, 2015.
Nina faced Justin Kish at UFC 195 on January 2, 2016 but lost the fight by unanimous decision.
However, when Jocelyn Jones faced Libarger at UFC Night on January 15, 2017; She won the fight by submission in the third round.
Similarly, she faced Angela Hill at UFC Fight Night on November 11, 2017 alongside Randa Markos at UFC on Fox on July 28th 2018 as well as Claudia Gadelha at UFC 231 on December 8, 2018, winning against them by completely unanimous decision.
Nina lost the fight against Tatiana Suarez on July 8, 2019 at UFC 238 by unanimous decision.
Later, on October 10, 2019, she publicly announced that she will hold her martial arts career in order to have her first child. His wife Amanda Nunes announced that she is expecting her first child in March 2020. Her daughter was later born in September 2020.
She lost her fight against Mackenzie Dern by first-round arm bar on April 10, 2021 at the UFC. She was scheduled to face Amanda Lemos at UFC Fight Night 199 on December 18, 2021, but was removed from the match for an unknown reason and replaced by Angela Hill.
On July 9, 2022, she was expected to face Cynthia Calvilo at flyweight at UFC on ESPN 39 but withdrew due to illness and was cancelled.
In 17 professional matches, she won 10 matches; 4 by knockout and decision as well as two by submission. I lost 2 of those matches by serving and 5 by decision.
However, in the amateur record collapse, she won all three of her matches. Two of them are by knockout and one by decision.
She won her first match against Sarah Seitz on January 11, 2008, with a score of 1–0 by succumbing to punches.
She won her second match against Kristi Tada by suspension on 24 April 2009 with a score of 2-0.
She won her third match against Jenny Yum by 3-0 on 20 March 2010 by unanimous decision.