The Bosnian-born immigrant was found guilty on all counts, including conspiracy to use weapons of mass destruction, conspiracy to commit murder and supporting a terrorist organization, CNN reported.
"I want to commend prosecutors for the conviction of Adis Medunjanin," New York Police Commissioner Ray Kelly said. "His conviction stands as a stark reminder of terrorists' desire long after 9/11 to return to the city to kill more New Yorkers."
Medunjanin, 28, pleaded not guilty to his role in the suicide mission assigned to him by al-Qaida while on a 2008 visit to Pakistan with two high school friends, Najibullaah Zazi and Zarein Ahmedzay. He said his intention was to join the Taliban to fight American troops in Afghanistan.
The FBI and the New York Police Department thwarted the bomb plot, days before it was to be executed, in September 2009.
Zazi and Zarein pleaded guilty in exchange for leniency and are awaiting sentencing, The New York Times reported. Medunjanin's sentencing is scheduled for Sept. 7.