A teenager was taken to hospital after what police described as an "out of control party" at Maitland's Polish Hall on Saturday night.
Police attended the Grant Street hall about 7.30pm after receiving numerous noise complaints about the party, which had been advertised on Facebook.
Police said they arrived to find between 200 and 300 young people in the hall and quickly moved to shut down the party.
A 17-year-old was conveyed to Maitland Hospital by ambulance after suffering a suspected drink spiking, police said.
Numerous police units were needed to safely disperse the crowd, but police said there were no major disputes or arrests made.
The hall was left with minor damage.