Fermin started her career as a political journalist, but soon turned towards writing for tabloids, about movie stars and other celebrities. Her first television appearance was when she became the main host of the weekend showbiz talk show Movie Magazine on GMA Network in 1987. In 1992, ABS-CBN hired Fermin to host the Sunday talk show Showbiz Lingo with Butch Francisco. Fermin's participation as main host of Showbiz Lingo had the blessings from her producers Inday Badiday, and did not run in conflict with Movie Magazine, which aired on Saturdays. But in 1994, Fermin eventually left Movie Magazine and GMA Network after she signed an exclusive talent contract with ABS-CBN, which in return capitalized on Fermin's new title as the '90s "Queen of Intrigues" by giving her the daily talk show Cristy Per Minute which started airing in 1995. During this period, her residence was in Valenzuela, Metro Manila.[2]
Fermin was suspended by the ABS-CBN management effective October 15, 2008, until December 31, 2008, on both The Buzz and the radio program Showbiz Mismo of DZMM, due to controversial rift issues between her and former actress Nadia Montenegro.[3][4]
On November 8, 2010, she returned to radio when her entertainment news program, Cristy FerMinute, was launched on Radyo5 92.3 News FM (now 92.3 Radyo5 True FM). The said program is also simulcast on AksyonTV (now One PH).
On July 28, 2012, TV5 Network Inc. canceled Paparazzi, while Juicy! was canceled on August 3. Fermin began hosting Ang Latest on August 4 of the same year.
On May 10, 2024, Sharon Cuneta and Francis Pangilinan filed with the Makati Prosecutors Office of Prosecutor Dindo G. Venturanza, Cybercrime Prevention Act of 2012complaints against Fermin. Britanico Sarmiento and Ringler Law Offices said the case is anchored on alleged defamation centering on the couple's "personal and family affairs.”[8] In Cristy FerMinute Fermin replied thereto - “Territorial po 'yan, 'cyber libel' -- it comes with the territory.”[9]