The brothers, whose names have not been released, were jet skiing on the bay Sunday night when they collided around 8 p.m., The (Newark, N.J.) Star-Ledger reported.
Both were taken to a local hospital where one man was pronounced dead a short time later, said Acting Sgt. Adam Grossman, a State Police spokesman. The other brother suffered minor injuries, Grossman said.
Toms River Police Chief Michael Mastronardy said the two victims were in their early 20s.
The cause of the collision has yet to be determined, Grossman said.