A group of readers who bought Armstrong's "It's Not About The Bike" and "Every Second Counts" sued in Sacramento federal court seeking class-action status and more than $5 million in damages. They said they were duped into believing the books were inspirational true accounts and should have been labeled fiction.
U.S. District Judge Morrison England's 39-page rule sided with Armstrong's attorneys, who argued the books are free speech protected by the First Amendment.
"Lance Armstrong has a right to exercise his First Amendment right to free speech," Armstrong attorney Zia Modabber said.
By law, the plaintiffs have 21 days to refile their lawsuit under the guidelines of Tuesday's ruling, but Modabber predicted the ruling would close the door on the case.
The ruling likely eliminates one of several legal hurdles facing Armstrong. The federal government is seeking to recover more than $30 million the U.S. Postal Service paid to sponsor his former team in a case that could include total penalties of more than $100 million.
Armstrong also has been sued in Texas by two companies seeking to recover $15 million in bonuses paid to Armstrong and his teams for winning the Tour de France and other races.
The books lawsuit was filed in California under that state's consumer protections laws. The lawsuit accused Armstrong and publishers Random House and Penguin Group of committing fraud, false advertising and other wrongdoing for publishing the cyclist's vehement denials that he wasn't a cheat. They also claimed the books should have been labeled as fiction instead of non-fiction.
"The fact Lance didn't tell the truth about whether or not he doped, does not make the entire story of his life fiction," Modabber said.
Armstrong vehemently denied doping for use for years, but admitted in a January interview with Oprah Winfrey that he cheated during most of his career. The confession came after a detailed report by the U.S. Anti-Doping Agency.