The incident occurred on Argon Street, by the Brussels-South railway station and several hotels.
"One person, whose name has not yet been identified, received two gunshot wounds, there is no threat to his life," the Brussels prosecutor's office said.
The prosecutor's office has opened an investigation into the attempted murder and begun "investigative actions, including examining the recording from CCTV cameras and ballistics," the office said, adding that the suspect or suspects have not been identified yet.
According to media reports, citing witnesses, two men opened fire but managed to escape. The victim, 28, is in hospital, his life is out of danger.