In the lawsuit filed Monday in Manhattan state Supreme Court, Roberto LeBron, 20, charged that he was kicked in the head after an encounter with Rhymes and his nine bodyguards in August 2006.
Rhymes' attorney, Scott Leemon, said he hadn't seen the lawsuit.
"Nothing has been proven yet," Leemon said.
The 35-year-old rapper, whose real name is Trevor Smith, faces trial for allegedly assaulting a fan after an Aug. 12, 2006, performance at a music festival on Randall's Island.
It wasn't immediately clear whether the lawsuit was connected to that incident.
Rhymes also faces separate trials on charges that he drove drunk, drove with a suspended license, and beat and kicked a former employee.
The rapper's hits include "Put Your Hands Where My Eyes Could See," "Dangerous" and "Touch It." He has also appeared in movies, including "Shaft" and "Finding Forrester."