Zima began her career at the age of 24 months when she was chosen as a toddler to appear in a television commercial for Downy fabric softener. She played the role of Grace Sheffield on the television show The Nanny for six years. Zima has become known for her work in films such as The Hand That Rocks the Cradle and appeared in the Hilary Duff film A Cinderella Story and Dimples, Looking for Sunday, Once in a Very Blue Moon and Legacy alongside Haylie Duff
In 2007, Zima played Mia Lewis, a sexually precocious and conniving 16-year old, on the series Californication. Zima returned for a second season of Californication in 2008. In promotion of Mia's book, Fucking and Punching, Zima starred in several Californication webisodes that are featured on YouTube. In 2009, Zima joined the cast of Heroes as Gretchen Berg, Claire Bennet's quirky bisexual roommate and tentative love interest.
She stars as Jill in the 2009 release The Collector.
