Originally from Manaus, Brazil, Martins began training in judo in 1994, which he continued with until the year 2000, reaching the rank of brown belt. Due to his desire to learn submissions, Martins began training in Brazilian jiu-jitsu in 1999. Martins went on to have an accomplished career in Brazilian jiu-jitsu, winning various titles. In 2004, needing to support his newly formed family, Martins began mixed martial arts.
Martins made his professional mixed martial arts debut in 2004, and compiled a 23–6 record on the Brazilian circuit before being signed by Strikeforce.
Martins was scheduled to make his Strikeforce debut against Isaac Vallie-Flagg on September 29, 2012 at Strikeforce: Melendez vs. Healy. However, the event was cancelled due to an injury to headliner Gilbert Melendez.
Martins faced Jorge Gurgel on January 12, 2013 at Strikeforce: Marquardt vs. Saffiedine. He won the fight via unanimous decision.
Martins made his promotional debut against Daron Cruickshank on November 9, 2013 at UFC Fight Night: Belfort vs. Henderson. He won via submission due to a straight armbar in the second round. The win also earned him his first Submission of the Night bonus award.
Martins faced Donald Cerrone on January 25, 2014 at UFC on Fox 10. He lost the fight via knockout in the first round.
Martins faced promotional newcomer Juan Puig on July 6, 2014 at The Ultimate Fighter 19 Finale. He won the fight via knockout in the first round, after landing a short, counter right hand.
Martins faced Rustam Khabilov on February 22, 2015 at UFC Fight Night 61. He won the fight by split decision. In the fight, he was able to take and knock Khabliov down at the end of the second round.
Martins faced Islam Makhachev at UFC 192 on October 3, 2015. He won the fight via knockout in the first round, which produced a Performance of the Night bonus.
Martins next faced Leonardo Santos on October 8, 2016 at UFC 204. Santos was awarded a split decision victory.
Martins faced Kajan Johnson on September 9, 2017 at UFC 215. He lost the fight via knockout in the third round.