De eerste UFC van 2012 zit er alweer op. Het decor voor UFC 142 was de HSBC Arena in Rio de Janeiro, Brazillië.

Maar liefst 11 UFC-vechters hadden de eer om in hun vaderland te vechten, waaronder de Braziliaan José Aldo. Aldo wist voor de vijfde keer op rij zijn titel met succes te verdedigen. Dit keer slaagde de Amerikaan Chad Mendes er niet in om Aldo van zijn troon te stoten. Maar liefst zes van de tien partijen werden al in de eerste ronde beslist.

Main PPV Card
 
Jose Aldo defeated Chad Mendes via Knockout (Knee, Punches) – Round 1, 4:49
Vitor Belfort defeated Anthony Johnson via Submission (rear-naked choke) – Round 1, 4:45
Rousimar Palhares defeated Mike Massenzio via Submission (heel hook) – Round 1, 1:03
Carlo Prater defeated Erick Silva via Disqualification (illegal punches) – Round 1, 0:29
Edson Barboza defeated Terry Etim via Knockout (spinning heel kick) – Round 3, 2:02
 
UFC on FX: PPV Prelims
 
Thiago Tavares defeated Sam Stout via Unanimous Decision
Gabriel Gonzaga defeated Ednaldo Oliveira via Submission (rear-naked choke) – Round 1, 3:22
Yuri Alcantara defeated Michihiro Omigawa via Unanimous Decision (30-27, 29-28, 30-27)
Mike Pyle defeated Ricardo Funch via TKO (strikes) – Round 1, 1:22
 
Fuel TV / Facebook Prelims
 
Felipe Arantes defeated Antonio Carvalho via Unanimous Decision (29-28, 29-28, 29-28)