The video, titled "Storming the Prison of Abu Ghraib," shows scenes of the battle from afar, as well as insurgents preparing a surprise attack.
One insurgent calculates how to hit the target, while others load up an improvised rocket launcher. The group claims to have fired 39 rockets.
Former military intelligence officer Rick Francona, now an NBC News analyst, says the video reveals a level of military competence.
"The zeroing in of the weapons and the launching of the rockets, and hitting what they aimed at, shows a certain skill level that we may not have accredited to the Zarqawi group," says Francona.
The flames in the distance appear to be rockets hitting their targets. A few seconds later, U.S. soldiers respond with gunfire. One large blast may be a suicide or roadside bomb.
"This is a particularly audacious attack because it appears that they were in no rush when they were setting up these weapons," says Francona. "They were taking their time. They were being very deliberate in their actions, and it was obviously broad daylight."
Zarqawi claims to have had spies inside and outside the prison. An Internet posting in December warned that Abu Ghraib was a target, because of abuses there.
On the Web site, Zarqawi dedicates the attack to Omar Yousef Jumah, a cleric from Jordan who left his family to fight in Iraq and was killed in a previous unsuccessful attack on Abu Ghraib.
The Pentagon would not comment on the video. Military analysts predict there will be more large scale attacks, as Zarqawi tries to prove his group is relevant and still to be feared.