Police caught patrons with ecstasy, cannabis and LSD during the four days of the Babylon Music Festival near St Arnaud.
A man, 23, was arrested for possessing a quantity of ecstasy and cannabis, while two men, 20 and 25, were arrested for trafficking cannabis, MDMA and LSD.
Two females, 26 and 24, were also cautioned for possessing MDMA and cannabis.
Police also seized cash from festival-goers who attempted to profit from selling illicit substances.
Senior Sergeant Rob Weppner said the majority of patrons were well-behaved, but was disappointed people were still bringing in illicit drugs.
“The amounts seized were quantities ready to be trafficked,” he said.
“We had a very visible and proactive police presence every day of the festival ensuring everyone there was having a good time.”
Up to 12 police personnel were present across the four days between 10-4am.
“Overall, there were no reported incidents of crimes against the person which includes assaults, including sexual or domestic violence assaults, or property crime including thefts, theft from motor vehicles or property damage,” Senior Sergeant Weppner said.
“These events are known to have violence or property crime, so in that regard it was good.”
Senior Sergeant Weppner said illicit drugs at music festivals was a concern and would continue to be a focus.
“Police operations to target illicit drugs and other criminal offences at these types of events will continue and will be something we always look for,” he said.