Large house parties could also be vulnerable to sneak-in thefts over the festival period.
The warnings are in a safety message from police in the Highlands and Islands.
Police Scotland said criminals targeted homes at this time of year to try and steal presents and money.
Insp Ewan Henderson said posts and other messages on social media sites before and during parties could alert thieves.
He said: "Christmas nights out are planned in advance, so just taking a few minutes to think about the security of your home will mean everyone's Christmas can be fun-filled.
"Posting photos on social media of nights out are an everyday occurrence.
"What we are asking is that you think about it before you post the messages. Are you inviting someone to break in to your home by advertising it is un-occupied? Could the messages be posted the next day?"
Peter Kirwan, of Neighbourhood Watch Scotland, added: "We're encouraging people to ask a neighbour to keep an eye on their house when they go away.
"Small things like moving curtains and taking in mail can help make a place look occupied and reduce the risk of a house breaking."
Christmas party selfies and other social media posts about festive nights out could alert thieves to unoccupied homes, police have warned.