The four men were sentenced in New York
All were members of Osama Bin Laden's al-Qaeda group, which is accused of being behind the 11 September attacks on New York and Washington that killed more than 5,000 people.
One of the men, Wadih el-Hage, a naturalised US citizen born in Lebanon who was convicted of conspiracy to bomb the embassies, gave a 30-minute address protesting his innocence and claiming to be a devout Muslim opposed to violence.
Two of the others, Tanzanian Khalfan Khamis Mohamed and Mohamed Rashid Daoud al-Owhali from Saudi Arabia, who were convicted of the most serious charges, were eligible for a death sentence but escaped the penalty when the jury failed to agree.
Mohamed was accused of making the bomb, and al-Owhali was charged with riding in the vehicle which carried the bomb to the building and tossing stun grenades at the guards.
The fourth accused, Jordanian Mohamed Saddiq Odeh, was an explosives expert who gave advice to the group.
Gratitude
El-Hage, a former personal secretary to Bin Laden, said: "The killing of innocent people is radical, extreme and cannot be tolerated by any religion, principles or values."
Mohamed declined to address the court, but made a statement through his lawyer to "express gratitude to a jury that spared his life".
More than 200 people died in the bombings.
Extraordinary security measures were in force at the courthouse, only a few blocks away from the ruins of the World Trade Center.
The four men were convicted in May following a five-month trial by an anonymous jury.
Judge Leonard Sand told the courtroom that "three members of the jury stated that life imprisonment is harsher than the death penalty".
Restitution payments
Odeh's lawyer, Anthony Reeko, said he would file an appeal on behalf of his client.
He said Odeh regretted the loss of life but not his role as a soldier in al-Qaeda.
Outside the courthouse Mr Reeko said: "He stands by the fact that he is a member of al-Qaeda and remains committed to al-Qaeda - but the two don't mean guilt."
Judge Sand ordered each of the men to pay $33m in restitution - $7m to the victims' families and $26m to the US Government.
At a pre-sentencing hearing on Wednesday, he acknowledged that they would be unable to pay, but suggested that assets frozen in the global war on terror might be used.
Relatives' appeals
Before sentencing, relatives of people killed in the bombings made appeals for life sentences.
Susan Hirsch, whose husband died in the bombing of the embassy in Tanzania, said the defendants gave a distorted view of Islam. Her husband, Jamal, was Muslim.
"There is nothing you could do to these individuals that would soothe the sorrow that haunts me," she told the judge.
Officials had feared that the sentencing could provoke symbolic attacks similar to those in New York and Washington.
Armed police and army reinforcements were on the streets, traffic was rerouted away from the courthouse, and metal detectors were installed in the building.
The four prisoners were fully chained, with US marshals standing behind them.