A worrying new study's found young men are more violent after Geelong wins a game.

The Deakin uni research has found people are 39 per cent more likely to end up in the Geelong Hospital emergency department after an assault on the days the Cats have a win.

They say males aged 18-24 are overwhelmingly the perpetrators and the victims.

But researchers say they did not find an association with alcohol, and the data doesn't show where the violence happens.

Barwon Health says it agrees with the findings, and that staff see an increase in intoxications and assaults when Geelong wins at home.