The city's major says this result will be seen as a return of "the Nazis in Germany"
Germany's right-wing anti-immigration party Alternative für Deutschland (AfD) has registered big gains in the German capital.
The party received 14.1% during Berlin's regional election, meaning that it is set to enter the state parliament for the first time.
Ahead of the election the city's mayor said that double-digit support for the party, "would be seen around the world as a sign of the return of the rightwing and the Nazis in Germany."
"Berlin is not any old city" the Social Democrat politician added, "Berlin is the city that transformed itself from the capital of Hitler’s Nazi Germany into a beacon of freedom, tolerance, diversity and social cohesion."
AfD said that its target was to sure 20% of the vote. It surprised analysts when it gained 21% support in Merkel’s home state of Mecklenburg Vorpommern in early September .
Angela Merkel’s Christian Democratic Union (CDU) received 17.5% - down from 23% in 2011. The party finished second to the centre-left Social Democrats who drew 21.6% of the vote - the Green Party was the third most popular with 15%.
The Social Democrats and CDU are likely to remain in control of the city, with the assistance of a third minor coalition partner.
Speaking after the results, Mrs Merkel acknowledged “very bitter” losses for her party, and reflected on the German response to the refugee crisis last year.
In a speech reported by The Guardian, she said: “For some time, we didn’t have enough control [...] No one wants a repeat of last year’s situation, including me."
She said if she could turn back time she would prepare "the whole government and the authorities for the situation which hit us out of the blue".
AfD is on-course to become the first far-right party to gain seats in the Bundestag since WWII - the national elections take place in October of next year.
“When we can reach double digits even on difficult turf like Berlin, then we are an established party,” Jörg Meuthen, AfD co-leader said.
The party's policy papers include headings such as "Islam is not part of Germany."