The 9th U.S. Circuit Court of Appeals in San Francisco refused to reconsider a ruling last month that rejected an appeal by Cameron and Tyler Winklevoss and a third classmate, Divya Narendra.
The Winklevosses and Narendra are seeking to challenge a $65 million settlement they reached with Palo Alto-based Facebook in federal court in San Jose in 2008.
They claim that Facebook failed to disclose the true value of shares that were part of the settlement.
In last month's decision, a three-judge panel said the twins were "sophisticated litigants" represented by a team of six lawyers and a financial expert, and that they should have known what they were doing when they signed a broad release of all claims.
The financial expert was the twins' father, a former accounting professor.
In today's action, the federal appeals court declined the twins' request to have an expanded 11-judge panel review the case.
The final remaining step in the case is a possible appeal to the U.S. Supreme Curt. Lawyers for the Winklevosses and Narendra were not immediately available for comment Monday.
Facebook spokesman Andrew Noyes said, "We're pleased with the court's decision."
In last month's ruling, Circuit Judge Alex Kozinski commented that the Winklevosses and Narendra in fact "made a deal that appears quite favorable" because Facebook shares are now worth three times more than what the twins thought they were worth at the time of the settlement.