The video shows the two Army privates — and best friends — at the hospital where they were taken following the March 23 ambush of the 507th Maintenance Co.
The tape was never aired in Iraq.
Piestewa, her face swollen and bruised and her head loosely bandaged, is shown as someone positions her feet, and then her head, for the camera shot. Her lip is shown curling back in an apparent grimace.
Lynch, 20, of Palestine, W.Va., is also shown bandaged, her lip cut.
Neither appears awake or alert.
"We had no idea that anyone had taped her or where this tape came from," Percy Piestewa, Lori's mother, told the Arizona Republic.
Piestewa told the newspaper that the family did not know Lori had been hospitalized with Lynch.
Telephone messages left with two spokespeople for Lynch's family were not immediately returned.
Iraqi doctors have previously said the women were brought to a private clinic following the ambush, and that Piestewa, a 23-year-old mother of two from Tuba City, Ariz., died half an hour later of severe head injuries.
Lynch was rescued by U.S. forces April 1, while five other soldiers were found about two weeks later elsewhere in Iraq. But 11 of their colleagues died during and after the ambush in Nasiriyah.
Piestewa was the first U.S. female service member to die in the war.
The identities of Lynch and Piestewa were verified for NBC by Spc. Shoshana Johnson, one of the rescued soldiers.
"It was a little shocking to see Lori, but it also gave me a little peace to know that they tried, they did their best for her," Johnson, 30, of El Paso, Texas, told the network. "I mean, it was obvious they tried to bandage her up and give her medical care."
NBC told the Army it had obtained the tape before airing it so the families of the soldiers could be told first, according to MSNBC.com.
Defense Department spokesman Jim Turner said Tuesday night officials were aware of the Iraqi video, but had not seen it and did not have details about what it contained.
The United States repeatedly bombed Iraqi TV studios after they aired interviews with American prisoners of war. But this tape survived because an employee at the state network kept it at home, NBC reported.