The reality TV star was treated in hospital after having his head split open with a bottle when the Canadian singer was involved in a row with another woman at the Hollywood Roosevelt Hotel in the early hours of this morning (07.11.11).
Security split up the fight and police were called to the hotel but Avril and the other woman had already left the scene.
According to TMZ.com, police listed in their report that Brody was a victim of an "assault with a deadly weapon".
The former 'Hills' star - who refused medical treatment at the hotel and instead took himself to hospital - later alluded to the incident on his twitter page.
He wrote: "'Interesting Saturday night. Just got of the hospital with a new scar on my face. Charges/chargers! (sic)"
Earlier in the evening, he had posted about how much he was enjoying himself with his 27-year-old girlfriend.
Alongside a picture of himself and Avril, Brody, 28, posted: "Having the best night with the love of my life @AvrilLavigne so happy right now!"