The shooting happened just after 7 p.m. at Rev James A. Polite Avenue in the Longwood section.
Police say the 18-year-old victim, identified as Joshua Sparrow, was shot in the head and torso.
He was taken to Lincoln Hospital where he was pronounced dead.
There's no word yet on what led up to the shooting, and police have not released a description of the suspect.
No arrests have been made, and the investigation is ongoing.
Monday night's deadly shooting in the Bronx marks the fifth teen killed across the five boroughs in less than one week, according to police.
The nightly string of killings began last Thursday in Harlem, where 16-year-old Clarence Jones was gunned down on West 124th Street.
The next night, 15-year-old Malachi Deberry was shot and killed just steps away from his home in East Flatbush, Brooklyn.
Over the weekend, 16-year-old Taearion Mungo was shot and killed at a housing project in Fort Greene on Saturday, and 15-year-old Tristan Sanders was gunned down in Crown Heights on Sunday.
No arrests have been made in any of the incidents.
This story will be updated as more information becomes available.
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