The woman was later allowed to vote in the western town of Bergheim after she complained to election authorities. Town officials have apologized for the incident.
The poll workers reportedly cited a ban on face coverings for not allowing her to vote, according to the local WDR public broadcaster. The law says those who wish to vote must be identifiable.
She was later allowed to vote after researching the law and complaining to city officials. The town's elections board said she is allowed to wear her headscarf and vote, while adding that restrictions on face coverings apply to more conservative forms of dress such as the burqa or niqab.
Video of the woman talking to poll workers circulated on social media. Users accused election workers of being Islamophobic or racist.
Bergheim officials have apologized for the incident.
"There are no excuses for this extraordinary misjudgement. Something like this simply should not happen," Bergheim Mayor Volker Miesseler said in a statement. Miesseler has spoken to the young woman by phone and is expected to personally meet with her in the coming days.
A statement from the town of Bergheim said there was no indication that the woman was turned away due to Islamophobic, racist, or discriminatory reasons.
The polling assistant dealing with the young woman "had assumed the veiling was impermissable, although the handling of any veiling was explicitly discussed during election worker training."
Although women wearing a headscarf are able to vote, an EU court earlier this year ruled that German employers can ban the coverings "in some cases."
The case was brought forward by two Muslim women in Germany who had lost their jobs due to their headscarves, with the court ruling drawing anger from religious associations.
Source: Deutsche Welle