Court personnel said it had been 60 years since justices had rejected an appeal petition and then reversed themselves and voted to hear the claim.
The switch may reflect frustration among the court's more liberal and centrist members over the Bush administration's handling of the Guantanamo issue, according to civil liberties lawyers who have been battling with the government.
Three years ago, the court ruled that the hundreds of prisoners at the U.S. military facility in southern Cuba were entitled to a hearing before a neutral judge to challenge the government's basis for holding them. In a rebuke to the high court, President Bush and the then-Republican-controlled Congress enacted a law to strip these "unlawful enemy combatants" of their right to be heard in the federal courts.
Friday's order may signal that a majority of the justices are prepared to rule that the Constitution's habeas corpus guarantee gives the Guantanamo detainees the right to go to court and contest the government's reason for holding them.
"The Supreme Court, along with the rest of the nation, should be sick and tired of what it's seeing in Guantanamo," said Matthew MacLean, an attorney for four Kuwaiti detainees at the prison. "It's anybody's guess what changed the Supreme Court's mind, but I hope the justices are seeing the discomfort that so many people in this country and abroad have with Guantanamo."
White House National Security Council spokesman Gordon Johndroe reacted to the justices' announcement by saying: "We did not think that court review at this time was necessary, but we are confident in our legal position."
The prison may be closed before the court acts. Defense Secretary Robert M. Gates has said he would like to move the detainees to another location, and congressional Democrats have threatened to cut off funding for the current facility.
Despite years of legal skirmishing, little progress has been made in establishing a system for deciding who is a dangerous foreign fighter who should be held prisoner.
Although former Defense Secretary Donald H. Rumsfeld once described the Guantanamo prisoners as the "worst of the worst," many of them have been released.
Since terrorism suspects were first brought to Guantanamo five years ago, the Bush administration has argued that foreign fighters who are not part of a regular army have no rights in American law and also are not prisoners of war entitled to rights under the Geneva Convention.
However, in response to the high court's 2004 ruling, the Pentagon did agree to review the status of each prisoner held at Guantanamo.
During a Combatant Status Review Tribunal, three military officers examine the evidence. The detainee does not have a lawyer.
Last week, an Army lawyer who has participated in several such hearings questioned their fairness. Lt. Col. Stephen Abraham filed a sworn statement in one appeal before the Supreme Court that said officers were pressured to rule in favor of keeping the detainees in prison as "enemy combatants."
"I certainly think the Abraham declaration proves what everyone has long surmised, that the CSRT process is just a kangaroo court that doesn't provide any meaningful review," said David Cynamon, the lead attorney in one of the cases the high court will consider, Al Odah vs. Bush. "It seems to be the straw that broke the camel's back."
Cynamon's client, a Kuwaiti named Fawzi Al Odah, has been held for six years with no charges filed against him.
The case has been consolidated with another involving six Algerian men who lived in Bosnia in the 1990s. They were arrested by Bosnian police in 2001 on suspicion of involvement in terrorism, but the following year the Supreme Court of Bosnia and Herzegovina ordered them released for lack of evidence.
They were immediately taken into custody by the U.S. military, shackled, put under hoods and shipped to Guantanamo, where they have been held since.
The lead plaintiff, Lakhdar Boumediene, was kept in a cold cell and deprived of sleep for 13 consecutive days, according to a report by the Center for Constitutional Rights, an advocacy group representing a number of the detainees.
In April, three of the court's liberal justices — Stephen G. Breyer, David H. Souter and Ruth Bader Ginsburg — voted to hear the pair of Guantanamo cases. Justices John Paul Stevens and Anthony M. Kennedy said they were willing to wait while the detainees and their lawyers went through an appeal process created by Congress, but the justices agreed that the issues involved were important.
The lawyers for Boumediene and Al Odah petitioned the justices to reconsider, because their clients faced many months of appeals that would almost certainly fail.
Friday's order did not say who voted to take up the case, but the lawyers involved assumed that Stevens and Kennedy had supplied the fourth and fifth votes.