Susan Edwards, 55, and Christopher Edwards, 57, each entered a plea of not guilty to two counts of murder at Nottingham Crown Court. They are accused of murdering William and Patricia Wycherley in May 1998.
The Wycherleys disappeared from their home in Mansfield, Nottinghamshire, in 1998. Police launched a murder investigation after their remains were found in the back garden in October. Tests showed they had been shot.
Mr and Mrs Edwards were remanded into custody. They will next appear at Nottingham Crown Court on March 21. A potential trial date has been set for June 2.