At around 6:30am, a 23-year-old man was shot in the central Alexanderplatz area. He was found lying in a doorway at the train station with life threatening injuries by passersby. Police said that the bullet went through his groin.
Paramedics were called to the scene and the victim was taken to one of the capital city's hospitals, where he received emergency surgery. He was reported to be in a critical condition.
The identity of the attacker is not known - nor is the motive behind the shooting. An investigation has been launched.
The attack came around just 24 hours after another man was shot elsewhere in the city. A 22-year-old was returning from a party at 5am when the group he was with was approached by a stranger.
An argument broke out and the attacker pulled out a gun and fired a shot into the air. The seven-strong group of friends tried to carry on walking but the young Berliner was shot in the stomach as he left.
Police are appealing for witnesses, and have been asking taxi drivers working in the Schöneberg area at the time if they say anything. So far, no clues have emerged.