The 18-year-old victim was walking north on Nostrand Avenue at 3:10 a.m. when a man approached him with a handgun, police said.
The suspect told the victim to raise his hands, then took his iPod, cellphone and $10, police said.
The suspect ran south toward Smith Street. The victim was not injured.
The suspect was described as about 5-feet-9 wearing black clothing and a ski mask.