Researchers found one in five workers have snogged a colleague at the Christmas party, while another one in ten have flirted with the boss.
Another 31 per cent just spend the night gossiping about their colleague or boss and 24 per cent embarrass themselves by dancing wildly on the dance floor.
Flirting with colleagues, falling over and telling workmates what they really think of them also leaves Brits feeling sorry for themselves the morning after.
But for almost one in 20, they are so embarrassed following their exploits at the Christmas party they have even quit their job. Don't say we didn't warn you.
The poll of 3,000 workers also revealed that 14 per cent are planning to use their Christmas party as a chance to kiss a colleague they have had their eye on for a while.
And one in ten is hoping the festive bash will even result in a relationship with that person.
Top Ten Christmas Party Sins
1. Gossiping about another colleague/your boss
2. Flirting with a colleague
3. Dancing ridiculously
4. Kissing a work colleague
5. Embarrassing yourself, such as falling over
6. Kissing a stranger
7. Flirting with your boss
8. Telling a colleague what you really thought of them
9. Telling your boss a secret you would prefer them not to know
10. Damaging or stealing something from the party
A spokesman for Oral B, which carried out the study, said: "Christmas parties are notorious for bad behaviour and an excess of food and drink."