The incident happened around 8:30 a.m. Monday on 36th Street, near 12th Avenue, in Borough Park.
The boy was sitting on his stoop when a man approached and began a conversation, trying to convince the child to go with him.
The boy's 9-year-old sister came outside, and the man fled on foot.
Detectives are now looking to talk to the man, who is described as being around 5-foot-11 with a pony tail.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).