The decision released Tuesday was the fifth rejecting Chapman for release, the New York Daily News reported.
Chapman shot Lennon on Dec. 8, 1980, in front of the Dakota, the New York apartment house where the former Beatle lived with his wife, Yoko Ono. He sentenced to 20 years to life in prison for the killing.
Ono wrote the Parole Board opposing release, saying that she feared for her own life and those of Lennon's two sons if Chapman is free. She told the News that Chapman himself might not be safe outside of prison.
A two-person Parole Board panel agreed that Chapman has had a clean record in prison for the past 14 years. But the board found that his good conduct doesn't outweigh his crime.
"Your conduct thus precipitated a horrendously tragic event which has impacted many individuals," the panel said in its ruling.