Norberto Rodriguez, 51, is charged with first-degree murder and concealment of a homicide, and is being held on $5 million bond.
He entered a not guilty plea before Judge Thomas Paul Panichi at Markham courthouse, according to Cook County State's Attorney's office spokesman Andy Conklin said.
The body of Irma Rodriguez, 45, an Oak Park mother of three, was found June 1, 2009, with multiple gunshot wounds in the trunk of her 2002 Pontiac Grand Am at 148th Street and Kilpatrick Avenue. She was days away from finalizing a divorce from Norberto Rodriguez.
Prosecutors said Irma Rodriguez disappeared from her home on May 32, 2009.