UFC 142: Aldo vs. Mendes was a mixed martial arts event held by the Ultimate Fighting Championship on January 14, 2012 at the HSBC Arena in Rio de Janeiro, Brazil.

UFC 142 featured preliminary fights live on Sportsnet.

Siyar Bahadurzada was scheduled to face Erick Silva, but pulled out of the bout. Veteran fighter Carlo Prater stepped in as a replacement for Bahadurzada.

Rob Broughton was scheduled to face Ednaldo Oliveira, but pulled out of the bout. Recently resigned heavyweight Gabriel Gonzaga replaced Broughton in the bout.

Paulo Thiago was scheduled to face Mike Pyle, but pulled out of the bout due to an injury. Recently resigned welterweight Ricardo Funch replaced Thiago in the bout.

Stanislav Nedkov was scheduled to take on Fabio Maldonado at this event, but visa problems forced Nedkov to withdraw from the bout. Newcomer Caio Magalhaes stepped in as a replacement for Nedkov in late December. However, Maldonado was injured less than a week before his fight with Magalhaes and the bout was scratched from the card.

The Ultimate Fighting Championship (UFC) is the largest Mixed Martial Arts promotion company in the world, which hosts most of the top-ranked fighters in the sport and produces events worldwide. Based in the United States, the UFC has eight weight divisions and enforces the Unified Rules of Mixed Martial Arts.Dana White serves as the president of the UFC while Frank and Lorenzo Fertitta control the UFC's parent company, Zuffa, LLC.

The first UFC event was held in 1993 in Denver, Colorado. The purpose of the event was to identify the most effective martial art in a real fight between competitors of different fighting disciplines, including Boxing, Brazilian Jiu-Jitsu, Tae Kwon Do, Wrestling, Muay Thai, Karate and other styles. In subsequent competitions, fighters ventured outside their base style to utilize effective techniques from other disciplines, which indirectly helped create an entirely separate style of fighting known as present-day mixed martial arts.

With a cable-television deal and expansion into Canada, Europe, Australia the Middle East,Asia and new markets within the United States, the UFC as of 2011^[update] has gained in popularity, along with greater mainstream-media coverage. As of 2001^[update] viewers can access UFC programming on pay-per-view television in the U.S., Brazil, Australia, Canada, New Zealand and Italy. UFC programming can also be found on FX, Fuel TV, and Fox in the U.S., on ESPN in the United Kingdom and Ireland, as well as in 150 countries and 22 different languages worldwide. UFC also carries a mobile site for on-the-go users and a Sports Bars page for fans to find places showing the pay-per-view. It is also available on the Roku streaming player.

Dana White (born July 28, 1969) is the current President of the Ultimate Fighting Championship (UFC), a mixed martial arts organization based in the United States.

Born in Manchester, Connecticut on July 28, 1969, White grew up in Las Vegas, Nevada, Ware, Massachusetts and Levant, Maine. White is a passionate Boston Red Sox fan. During his youth, he bounced back and forth between Boston and Maine. He attended the University of Massachusetts Boston but did not finish; however, while there he did launch a boxing program for inner-city youth.

White has a background as an aerobics instructor. In 1992, White established Dana White Enterprises in Las Vegas. He conducted aerobics classes at three gyms in the Las Vegas area and began managing MMA fighters Tito Ortiz and Chuck Liddell.

While working as a manager, White learned that Semaphore Entertainment Group, the parent company of the UFC, was looking for a buyer for the UFC. White contacted childhood friend Lorenzo Fertitta, an executive at Station Casinos, and a former commissioner of the Nevada State Athletic Commission. Within a month, Lorenzo and his older brother Frank bought the UFC, with White installed as its president. White currently owns about 9% of Zuffa, LLC, the entity the Fertitta brothers created to own and manage the UFC.

Edson Mendes Barboza Jr. (born January 21, 1986), better known as Edson Barboza, is a Brazilian professional mixed martial artist who competes in the lightweight division. A professional MMA competitor since 2009, Barboza is a former Ring of Combat Lightweight champion and is currently competing in the Ultimate Fighting Championship.

Barboza comes from Nova Friburgo, Rio de Janeiro. His fighting style incorporates Muay Thai and Taekwondo. His professional Muay Thai record is 28-3 with 22 victories by knockout and 17 first round finishes. Barboza moved to the United States in January 2009 and joined "The Armory" [1] in Jupiter, Florida.

Barboza's professional MMA career began in April 2009 in Tampa, Florida, when he defeated Aaron Steadman via TKO due to punches midway through the first round. Barboza then defeated Lee King twice in the Renaissance MMA promotion, first via second round knockout, then submission.

Barboza then joined New Jersey-based promotion Ring of Combat, making his promotional debut at Ring of Combat 28 against Nabih Barakat. Barboza knocked Barakat out in 69 seconds.

Terence Lee "Terry" Etim (born January 11, 1986) is an English mixed martial artist and Thai boxer who trains with Team Kaobon and RFT. He is trained by Colin Heron and Marcelo Brigadeiro. Etim is a brown belt in Luta Livre under Marcelo Brigadeiro.

Terry became the Cage Gladiators Lightweight Champion by defeating Greg Loughran via rear naked choke in the second round and successfully defended his title against Sami Berik, again winning in the second round via arm bar.

Etim's fight with Spain's Diego Gonzalez was refereed by former boxing World Heavyweight Champion Mike Tyson, during the World Cage Fighting Championships at the MEN Arena in Manchester, England in March 2006. Etim won the fight via triangle choke in the first round.

Since then Etim trained with Pride veteran Luciano Azevedo in Brazil in preparation for his fight with Matt Grice at UFC 70 in Manchester. After an opening flurry that rocked Grice, Etim jumped in with a flying knee that was blocked and caused him to fall to the canvas. From there, Grice worked his ground and pound attack, but once the fight was stood up, Etim turned the tables and locked in a standing guillotine. Etim dragged Grice down to the ground whilst in the guillotine. But this allowed Grice to escape briefly, before Etim got Grice in another guillotine choke. Grice fell unconscious in the choke and referee Steve Mazzagatti called the fight with 12 seconds left of the opening round.