Yulia Navalnaya, the widow of the late opposition leader Alexei Navalny, was queueing to cast her ballot at the Russian embassy in Berlin on Sunday, an AFP journalist witnessed.
Wearing a black jacket, Navalnaya received flowers from supporters and chatted with fellow voters in the long queue outside the embassy in the German capital.
Navalnaya had called on Russians to stage an election day protest against President Vladimir Putin by forming long queues outside voting stations.
Among voters who joined the snaking line in Berlin was Maria Katkova, 33, who told AFP that she was there "because I don't want my vote to be stolen".
"I want to be together with all these people here and feel like I'm not alone," said Katkova, who had been in the queue for two hours.
Stanislav Vliasov, 33, a risk manager, said that he had come to vote because "it's a good possibility to show a picture to all people around the world, to people in Russia... that people are against this situation... against the politics in Russia.
"People know there is a lot to do after today, the world has a lot to do to fight Putin's regime," he added.