An Iraqi court sentenced Ali Hassan al-Majeed, the Saddam Hussein-era official known as "Chemical Ali", to death by hanging for a 1988 gas attack that killed about 5,000 Kurds.
Majeed, a cousin of Saddam's who earned his nickname because of his use of poison gas, already faces death sentences in several other cases.
The Iraqi High Tribunal also sentenced former Defence Minister Sultan Hashem to 15 years in prison for the attack on the Kurdish town of Halabja.
Majeed was captured in August 2003, five months after US forces invaded Iraq and ousted Saddam.
He was sentenced to hang in June 2007 for his role in a military campaign against ethnic Kurds, codenamed Anfal, that lasted from February to August of 1988.
Majeed also received a death sentence in December 2008 for his role in crushing a Shi'ite revolt after the 1991 Gulf War and another for his involvement in killing and displacing Shi'ite Muslims in 1999.