Gul Agha Rouhani, Kabul's deputy police chief, said the woman was taken by two gunmen who stopped her car early Monday morning.
The woman, who has not been identified, is believed to be employed by German government aid agency GIZ, AP reported.
No comment was immediately available from the German embassy or GIZ in Kabul. The German Foreign Office and GIZ head office in Germany also did not comment.
Security in Kabul has deteriorated in recent months as Taliban insurgents have intensified their war against the Kabul government.
The insurgents have repeatedly said they would deliberately target foreigners. In recent months insurgents have launched a series of deadly attacks on offices, residential compounds and guest houses occupied by foreign nationals.
As the economy deteriorates and jobs dry up, abduction for ransom is also becoming more common, though mainly targeting Afghans.
Foreigners are seen as potentially lucrative kidnap victims, and while many live within strict security parameters, security measures such as armored cars can raise their profile for would-be kidnappers.
Earlier this year, a German national working with GIZ in northern Afghanistan was kidnapped as he drove through an area of Kunduz province called Ali Abad, well known as a hotbed of insurgent activity.
He escaped in May after being held for six weeks.