Clementina Cantoni, 32, a worker for CARE International, responded to prompts from a man not shown on the video, identifying herself and naming her father, mother and an uncle.
The tape, broadcast on Sunday by independent Tolo TV, then zoomed in on her face. She wore a blue scarf, spoke quietly and looked nervous.
It was not clear when the recording was made. But near the end of the tape, the man who was speaking off-camera asked Cantoni the date. "Today is May 28, Sunday," she said.
The date referred to Saturday and the discrepancy could not be explained. Cantoni was abducted on 16 May, dragged from a car by four armed men as she was being driven to her home in Kabul, the capital.
She has been in Afghanistan since 2002 and was working on a project helping Afghan widows and their families.
The TV station did not say how it had obtained the tape. The Italian Foreign Ministry confirmed the woman on the video was Cantoni.
Authorities have said they suspect the kidnapping was the work of the same criminal gang accused of abducting three UN workers last year. They were released a month later.
The director for CARE International in Afghanistan, Paul Barker, said he had seen the video and he did not see any obvious signs that Cantoni was ill or had been mistreated.
Government officials could not be reached for comment. Afghan President Hamid Karzai on Friday paid tribute to Cantoni, calling her a "daughter of Afghanistan."
Posters seeking information about her have been plastered across the city, and Afghan widows who benefited from her aid work have held rallies demanding her release.
Sunday's broadcast along with others recently will reinforce fears that militants or criminals here are copying tactics used in Iraq.
CARE's British director in Iraq, Margaret Hassan, was kidnapped in Baghdad in October and believed killed after pleading for her life on a video, although her body has not been recovered.
Three UN workers also were abducted in Afghanistan last year and held for a month before being released. They had been recorded pleading for their freedom on a video that was broadcast by the media.
Nato took command of security in
Afghanistan in August 2003
Meanwhile, an explosion shook the headquarters of Nato's 8000-strong security force in the Afghan capital on Monday; but there were no immediate reports of injuries, a spokeswoman for the force said.
The blast occurred "in the vicinity" of the International Security Assistance Force compound, said Leiutenant Colonel Karen Tissot Van Patot. She said officers were investigating the cause of the explosion.
An Afghan police officer outside the compound, speaking on condition of anonymity, said a rocket had hit inside the heavily fortified base, which is near the US Embassy and other diplomatic missions in central Kabul.
After a winter lull, loyalists of Afghanistan's ousted Taliban regime and other fighters opposed to President Hamid Karzai's US-backed government have ramped up their resistence with a series of bombings and other attacks.
US-led coalition forces and Afghan troops have hit back hard, killing nearly 200 suspected fighters and capturing dozens since March.