Parliament attack convict Afzal Guru was hanged at Delhi's Tihar Jail on Saturday, Union home minister Sushil Kumar Shinde said.
The execution took place at 8am. Guru will be buried at the jail, where he had been lodged for nearly eight years.
According to reports, the home ministry had recommended the death sentence on January 23 and President Pranab Mukherjee rejected his mercy petition on January 26.
Curfew has been imposed in several areas of Jammu and Kashmir, including capital Srinagar and Sopore, Guru´s hometown.
The convict´s execution was initially scheduled for October 20, 2006. But it was stayed after Guru´s wife filed a mercy petition with the President.
In December 2001, nine people were killed when five terrorists drove into the Parliament complex and opened fire. All the terrorists were shot dead.
Guru was arrested shortly after the attack and accused of planning it.