Born in Curitiba, Farfus first tasted racing in minibike races and won the local championships in 1991.
Like many drivers, his motorsport career began with karting. In 1992, at the age of 9 years, he won the Paraná state championship (cadet class), and mainly competed in São Paulo states championship from 1993 to 1998. In 1999 he succeeded in both winning the Italian Winter Cup and finishing runner-up in the North American Championship.
From 2004 to 2006 Farfus was a factory Alfa Romeo (N.Technology) driver in the European Touring Car Championship and later, the World Touring Car Championship.
In the 2006 season Farfus fought for the title against Andy Priaulx and Jörg Müller until the final race in Macau, but his outdated Alfa Romeo 156 wasn't up to the pace, and Farfus ended the season in 3rd place.
On 3 December 2018, it was announced that Farfus will join Hyundai for the 2019 World Touring Car Cup season, partnering the series's inaugural driver's champion, Gabriele Tarquini , Norbert Michelisz and Nicky Catsburg.