The 46-year-old man fell from the Oberbaum Bridge linking Kreuzberg with Friedrichshain at 3.40am. Police said in a statement he had been climbing the bridge with his 27-year-old friend when he slipped and fell into the river.
He grabbed onto a pillar at the bottom of the bridge and then tried to swim to shore but drowned, The Local Germany reported.
Passers-by and several of his friends jumped into the water and dragged him to shore.
Paramedics attempted to resuscitate the man at the shore but failed. He was pronounced dead in the ambulance.