Earlier this year the Vancouver Canuck had vowed to fight criminal prosecution, but he told a Vancouver judge he was guilty of assaulting on-ice opponent Steven Moore of the Colorado Avalanche, the CBC reported.
The judge also heard from Moore's Canadian lawyer, who asked that his client be allowed to deliver a victim impact statement before sentencing. Moore was unable to participate because he did not learn of Wednesday's proceeding until Monday.
The judge said he would announce later when sentencing would be decided.
On March 8, Bertuzzi grabbed Moore from behind and delivered a round-house right to his head. As Moore fell to the ice face first Bertuzzi, who weighs 245 pounds, jumped on his back. As soon as Moore's face hit the ice, Bertuzzi wound up to deliver another punch but was restrained.
The attack broke three of Moore's vertebrae in his neck and left him with a concussion. It is not known if Moore will play hockey again.
The guilty plea could open the way for the NHL to lift its indefinite ban on Bertuzzi, who remains hugely popular with Vancouver fans.