42 people were arrested for drug offences at a Melbourne music festival yesterday.

Melbourne police say they're alarmed music fans aren't heeding their warnings after 42 people were arrested for drug offences at a Melbourne music festival yesterday.

Trained police sniffer dogs uncovered ecstasy, amphetamines and cannabis during a blitz at the Parklife Music Festival at the Myer Music Bowl.

Forty of those arrested have been referred to a drug diversion program while two were questioned in relation to drug trafficking.

Acting Inspector Donald Brown says he's disappointed their message still isn't getting through but says they will be standing firm that illicit drug use won't be tolerated at upcoming summer music festivals.