The 22-year-old woman, said to have been married to a member of a hardline Taliban militant group, was shot dead after being accused of adultery with a Taliban commander.
The horrific video shows a crowd of men gather to watch a rifle-wielding gunman shoot her in the head and back during the execution in Qimchok village, in Afghanistan's Parwan province.
The unidentified shooter, who is seen wearing an orange beret, swiftly executes her - but continues to shoot her dead body while walking towards it. In all, nine shots were fired.
Officials in Afghanistan, where the amateur video was filmed, believe the woman was executed because two Taliban commanders had a dispute over her, according to the governor of the province where the killing took place.
Both apparently had some kind of relationship with the woman, said Parwan province governor Abdul Basir Salangi.
"In order to save face," they accused her of adultery, Salangi was quoted as saying by CNN.
Then they "faked a court to decide about the fate of this woman and in one hour, they executed the woman," he added.
Both Taliban commanders were subsequently killed by a third Taliban commander, Salangi said.
It is not clear from the video when it was filmed.