43-year-old Miguel Torres entered the plea Thursday in Berks County Court.
Torres has been held without bail on first-degree murder charges since Nov. 22, when he was returned to Reading from Bologna, Italy. He was captured several months earlier by Italian authorities working with the U.S. Marshals Service.
Authorities say Torres ambushed and gunned down his estranged wife Barbara West-Torres in September 2005 after she obtained a protective order against him.
Under conditions of Torres' extradition, prosecutors agreed to not seek the death penalty.
Torres' attorney said he's considering asking the judge in the case to assign an out-of-county jury for the trial.