To promote the band, all five artists appeared in commercials. Together with Girls’ Generation, f(x) performed in an ad of a new smartphone LG Chocolate. They recorded a single “Chocolate Love”, which appeared in October 2009. In 2010, the band filmed an ad for LG Cyon.
In May 2010, the group recorded its first EP, Nu ABO. It featured six songs, "Mr. Boogie", "Ice Cream", "Surprise Party", "ME+U", "Nu ABO", and a duo by Luna and Krystal "Sorry (Dear Daddy)". The debut EP reached the second spot of South Korea Gaon Albums Chart. At that time, many organizers tried to book f(x) for private events.
In 2010, the group went on its first tour. Together with other SM Entertainment’s groups, they performed on SM Town Live '10 World Tour.
The debut LP, Pinocchio, came out in April 2011. It was also re-released under the name Hot Summer in June 2011. The new version featured four new songs. The first version topped the national chart while the second one climbed to the 2nd spot. Both of them sold about 70,000 copies. The most popular tracks were "Pinocchio (Danger)", "Beautiful Goodbye", "Sweet Witches", "Gangsta Boy", and "Stand Up!".
In June 2012, the group presented its new EP, Electric Shock. The album topped South Korea Gaon Albums Chart and came in 2nd on Billboard’s World Albums Chart. The EP brought the group international recognition.
In 2013, f(x) recorded an LP, Pink Tape. It topped South Korea Gaon Albums Chart and Billboard’s World Albums Chart. The album also became popular in Japan. A single with an interesting name "Rum Pum Pum Pum" turned out to be a huge hit in South Korea.
In 2012 and 2013, the musicians went on two more tours arranged by the label, SM Town Live World Tour III and SM Town Week (with EXO).
In 2014, the group released one more LP, Red Light. It topped the national chart and came in second on Billboard’s World Albums Chart. The album featured such popular songs as "Butterfly", "Red Light", "All Night", and "Vacance"
In October 2015, f(x) presented another LP, 4 Walls. It was the first album recorded by just four members since Sulli left earlier that year. The album earned high scores from the critics. It topped South Korea Gaon Albums Chart and Billboard’s World Albums Chart. The single “4 Walls” became a hit, topping the national chart and selling 750,000 copies.
In 2016, the band released a video album for its Japanese audience, f(x) Dimension 4 – Docking Station in Japan. It was recorded in Korean and Japanese languages. The same year, f (x) went on SM Town Live World Tour V.
The group continues recording new songs and performing live.