Martin Tankleff, 36, was released on $1 million bail and thanked his friends, supporters and witnesses who came forward "because it was the right thing to do."
An appeals court threw out Tankleff's 1990 conviction last week, saying new evidence suggested someone else might have killed Seymour and Arlene Tankleff in their Long Island home.
Tankleff was 17 when his parents were bludgeoned and stabbed in their house in 1988. After a detective falsely told the teen his father had awakened from a coma and implicated him, Tankleff confessed to the crimes. But he quickly withdrew the confession, refusing to sign a statement police had prepared.
He was sentenced to 50 years to life in prison after being convicted in one of the nation's first televised trials.
Private detectives working on Tankleff's behalf later turned up witnesses who implicated a business partner of his father's and others in the killings. The Appellate Division of state Supreme Court in Brooklyn said it was probable that a new jury would render a different verdict if given a chance to hear all the evidence now available, including how the police obtained Tankleff's confession.
Relatives paid the bail, allowing Tankleff to leave the courthouse after the hearing in Riverhead, N.Y., 75 miles east of Manhattan. Suffolk County District Attorney Thomas Spota did not immediately say whether he would seek to prosecute Tankleff again.