The actress has filed a $100 million lawsuit claiming a television ad for the Wall Street firm that aired during the Super Bowl and Olympics was modeled after her.
Talking babies in the ad engage in chatter that refers to "milkaholic Lindsay." The 23-year-old actress has famously sought substance abuse treatment.
Lohan's name was never mentioned. But her New York lawyer contends that "Lindsay" is an equally recognizable moniker for her client - like that of Oprah or Madonna.
Lohan's legal team is seeking an injunction to stop future airings.
An E-Trade spokeswoman is declining to comment.