Aileen Wuornos had a difficult and cruel childhood plagued by abuse and drug use in Michigan, becoming a prostitute (and pregnant) by the age of 13. Wuornos eventually moved to Florida where she became a highway prostitute, servicing the desires of semi-truck drivers.

This movie focuses on the nine month period in 1989 and 1990 during which she had a lesbian relationship with a woman named Selby, and during which she also began murdering any of her clientele who tried to rape her.