Abu said Thursday that he "will be returning to the place that I call home, NC State."
He submitted his name for draft evaluation in March but did not hire an agent and had the option to return to school.
Abu is the Wolfpack's top returning scorer and rebounder, averaging 12.9 points and 8.8 rebounds per game last season.
NC State is awaiting a decision from fellow big man BeeJay Anya, who also entered the draft but can withdraw and return. Underclassman Anthony "Cat" Barber has signed with an agent.
Abu's decision came days after NC State signed two more freshmen for this season, including 7-foot center Omer Yurtseven.