Judge Sam Sparks of the U.S. District Court for the Western district of Texas granted MySpace's motion to dismiss the charges of negligence, fraud and negligent misrepresentation.
The high profile suit was filed last year by the family of the Austin, Texas, girl, who was attacked by a 19-year-old man she met on the Web site.
The suit andmade the popular service a target of child protection advocates. MySpace users share information about their lives by posting photos, blogs and videos.
In dismissing the suit, Judge Sparks said that as an "interactive service," MySpace was protected from materials posted on its site by the Communications Decency Act (CDA) of 1996. Sparks explained that the CDA is aimed at allowing Internet and other interactive services to continue to develop.
"To ensure that Web site operators and other interactive computer services would not be crippled by lawsuits arising out of third party communications, the Act provides interactive computer services with immunity," Sparks' ruling said.
Sparks noted also that the girl lied about her age, posing as an 18-year-old when she was only 13, and registered for an account. MySpace's minimum age requirement is 14. The girl's name was not divulged because of her age.
Adam Loewy, a partner in Austin-based law firm Barry & Loewy, who represented the family, said they planned to appeal the dismissal of the negligence charge and to refile charges of fraud and misrepresentation in a different court "in the very near future."
"We intend to fully prevail in this litigation," Loewy said.
MySpace separately faces several other lawsuits filed in state court in Los Angeles by families of teenage girl victims of predators they met on the service.
Carl Tobias, a law professor at the University of Richmond, said the ruling could be "persuasive" to the remaining suits, which were filed in state court. But Sparks' decision in federal court would not be binding.
Family protection groups have criticized MySpace, saying the Rupert Murdoch-controlled company had failed to provide safeguards such as age verification rules to protect its large group of teen users.