Zimmermann has been active in dubbing since the nineties, frequently dubbing Kathryn Hahn (including Crossing Jordan), June Diane Raphael, and Marisa Tomei, as well as Claudia Black in the Stargate franchise. She has been busiest in anime, heard in the Ghost in the Shell franchise (Lt. Col. Kurtz), Digimon (Gatomon and others) and Love Hina (Haruka). Other animation roles include Gloria in Happy Feet, Catwoman in Batman: Year One, and Hera in Wonder Woman. She has had character roles in the video games Jack Keane and Ankh: Battle of the Gods. For the English dub of Life Is Beautiful, she dubbed one of the female guards.