Roma Maffia began her acting career in Off-Broadway and Off-Off-Broadway productions. In the early 1990s, casting director Jane Jenkins asked her to audition for a role in the feature film The Paper, which was directed by Ron Howard. Soon after, she got a role on the television series Chicago Hope. Maffia's television career continued as she played 'Grace Alvarez,' the forensic pathologist for the Violent Crimes Task Force for four seasons on NBC's Profiler. She has had guest-starring and recurring roles on shows such as ER, Law & Order, The West Wing, and The Sopranos. As of 2006, Maffia stars as Liz Cruz on the FX Network series Nip/Tuck, the anesthesiologist to two dysfunctional plastic surgeons.

Liz Cruz is anesthesiologist for McNamara/Troy and doctor De La Mer. Often the 'voice of reason' at McNamara/Troy, Liz is a 40-something-year-old lesbian and feminist who often serves as a sarcastic foil for Christian Troy, though she occasionally shows concern and even admiration for Christian. She seems to have a proclivity towards physical injury, once being shot in the leg by Escobar Gallardo, and, more recently, having one of her kidneys stolen by organ thieves after being seduced and drugged by an attractive young woman.