Russian opposition politician Alexei Navalny was seen walking down the stairs in a photo posted on his Instagram feed on Saturday (September 19).
It comes five days after a Berlin hospital said he had been taken off a ventilator and could breathe independently.
Navalny is the leading opponent of Russian President Vladimir Putin.
He fell ill in Siberia last month and was airlifted to Berlin.
Germany says laboratory tests in three countries determined he was poisoned with a Novichok nerve agent.
Western governments have demanded an explanation from Russia.
In the post Navalny said he still could not use his phone and had difficulties trying to pour water into a glass.
But he praised his doctors, writing:
"They have turned me from a 'technically alive human being' into someone who has high chances to become... a man who can quickly scroll Instagram and understands without thinking where to put his likes."