Fiorentino got her first professional role in 1985 when she starred in Vision Quest.
She then starred in the action film Gotcha! which was filmed in the U.S., Paris, and East Berlin. Her co-star, Anthony Edwards, later directed her in Charlie's Ghost Story.
It was not until 1994 that she became widely recognized, receiving accolades for her performance in a modern film noir, The Last Seduction, as the murderous femme fatale, Bridget. Because The Last Seduction was first aired on HBO television, Fiorentino was ineligible for an Academy Award nomination for Best Actress, despite glowing reviews.