The justices declined to explain their decision -- a decision that was not entirely unexpected since this is the fifth time the Supreme Court has declined to intervene in the Schiavo case.
Late Wednesday, Schiavo's parents Bob and Mary Schindler filed an emergency appeal with the high court after the 11th U.S. Circuit Court of Appeals in Atlanta ruled that Schiavo's feeding tube could not be reinserted.
The family's new request argued that Congress intended for Schiavo's tube to be reinserted, at least temporarily, when it passed an extraordinary bill last weekend giving federal courts authority to fully review her case.
In his response, Michael Schiavo urged the justices not to intervene because his wife's case already has been endlessly litigated and at each turn courts have sided with him. The filing said, "That is not an exercise of legislative power, but trial by legislature."
The appeal went to Justice Anthony Kennedy, who is responsible for emergency appeals from the 11th Circuit. He referred the case to the other justices who declined to get involved.
Schiavo's feeding tube was disconnected March 18 on the orders of a state judge, which led to an extraordinary push by Congress to pass a bill, which President Bush quickly signed, to have Schiavo's case reviewed by federal courts.
Since the removal of her feeding tube, doctors have said that Schiavo would not survive more than a week or two without food and water.
Later Thursday, Florida Circuit Judge George Greer rejected a petition by the state's Department of Children and Families to take custody of Schiavo, which would have led to the reinsertion of her feeding tube.