Iyman Faris, an Ohio lorry driver, had initially admitted to surveying the bridge for exploring ways to destroy it, but subsequently tried to withdraw his guilty plea.
US District Judge Leonie Brinkema gave the maximum term after rejecting a request by Faris to withdraw the guilty plea. She said he knowingly pleaded guilty and that his credibility was "in serious question".
Faris, a naturalised US citizen, pleaded guilty on 1 May to one count of providing material support to al-Qaida and another count of conspiracy to provide material support to the banned group.
Born in Kashmir, Faris, 34, came to the US in 1994. He became a US citizen five years later.
He did not show much emotion as the judge sentenced him.
"I am innocent of this charge," Faris told the judge in brief remarks. "I don’t have any connection to al-Qaida except that a friend was a member of the group," he said.
His lawyer said the story about the Brooklyn Bridge was not true and Faris had only wanted to fool the FBI investigators so that he could "write a book".
US Justice Department officials said Faris met Usama bin Ladin at a training camp in Afghanistan several years ago and that he checked out the Brooklyn Bridge to determine whether it could be destroyed.
They also claimed that a top al-Qaida member, Khalid Shaikh Muhammad, had spoken to Faris in Pakistan last year about destroying the bridge.