Born and raised in the city of Rondonopolis, Santos did not have a particularly safe upbringing; at the age of 12, he was introduced to cockfighting, which was popular and not yet illegal in Brazil.

Santos turned professional when he was 20 years old and began his career 2-0 before facing legendary Brazilian fighter Jose "Pele" Landi-Jons, losing by TKO.

Santos won his next two fights, including a majority decision over future UFC veteran Francis Carmont before making his debut in PRIDE FC.

Santos also lost his next fight against Armenian superstar Gegard Mousasi by TKO before making his debut in World Victory Road Presents: Sengoku Raiden Championships against Makoto Takimoto, winning by an achilles lock.

Santos fought once more for the Japanese organization against future UFC veteran Siyar Bahadurzada, losing by TKO after receiving an arm injury.

Santos challenged Strikeforce Welterweight Champion Nick Diaz for the title on January 29, 2011, at the HP Pavilion in San Jose, California.

Santos made his organizational debut April 22 on the main card of Bellator 153 in a welterweight matchup beating Brennan Ward via first round submission.

On July 16, 2016, Santos faced Michael "Venom" Page and was defeated via KO by a flying knee, resulting in a frontal sinus fracture.