The militants snatched on Thursday a vehicle carrying the 15 medical staff, but released the hostages the same day after their identity was made clear, Outlook newspaper quoted Abdul Hayee Razmal, deputy director of the provincial health bureau, as saying.
One freed health worker, Ali Ahmad, gave details to journalists in Kandahar.
The vehicle was on the way to a clinic in Ziari district when armed Taliban militants intercepted it. "They freed us after realizing all of us are health workers."
Meanwhile, Qari Muhammad Yousuf, a purported Taliban spokesman, told the press that the Taliban took away the vehicle and freed the hostages after learning their identity.
Kandahar has been a hotbed of Taliban and other anti-government insurgents.
Militants have occasionally abducted employees of the government and foreign companies or organisations in this volatile province.