Berlin, Mar 18 Some 30,000 demonstrators, who police said were mainly of Kurdish origin, rallied in Frankfurt today calling for "democracy in Turkey" and "freedom for Kurdistan".
Significantly more people turned up than organisers had been expecting for the rally which took place on the Kurdish New Year's Day.
Militants in Turkey have for decades been seeking greater rights and autonomy for the nation's Kurdish minority.
Today's protest march in Frankfurt went off peacefully, a police spokesman said.
Some of the participants carried flags and banners of the outlawed Kurdistan Workers' Party (PKK), as well as portraits of Kurdish nationalist leader Abdullah Ocalan.
Police said no banners or flags were confiscated so as to not provoke the crowd, but added that photos had been taken which could lead to future prosecutions.
The PKK has been waging an insurgency against the Turkish state since 1984 that has killed over 40,000 people.
Turkish President Recep Tayyip Erdogan on Monday accused German Chancellor Angela Merkel of "supporting terrorists", part of a spiralling diplomatic row.
Turkey has long accused Germany of providing refuge to Kurdish and other militants.
A Merkel spokesman described Erdogan's jibe as "clearly absurd".
Erdogan has also accused Germany of "Nazi practices" for blocking his ministers from speaking to Turkish voters ahead of an April referendum on boosting his powers.
Germany is home to the largest Turkish diaspora in the world, as well as a significant Kurdish community.