The Pajhwok Afghan News said the woman worked for the Asian Rural Life Development Foundation and she was wearing a burqa over her head when she was pulled out of the car on the way to work in the suburbs of Kandahar.
It is the first reported kidnapping of a U.S. citizen in Afghanistan in recent years, although a number of Westerners, including two Germans and two Italians, were kidnapped in a violence-prone country last year.
Afghanistan, where the Taliban regime was overthrown in the 2001 U.S.-led campaign, has seen a rise in violence in the last two years. The country is also the world's leader in opium trade, with almost all its arable lands being sown with poppy.
Taliban officials have not confirmed yet whether the Islamic militants were responsible for the kidnapping.