If you are having alcoholic beveragesThey ought to figure it out from that.....
And if someone is so rude as to bring their child to what is obviously an adult party....offer the 5 year old a martini!
Seroiusly....if you can't be sure no kids will show up....you will need to put " Adult Party" somewhere on the invitation.
Linda C

I agree that "cocktails" would signify, as would putting only the adults names on the invite. You could also specify something like "holiday dress" which I think would indicate adults only as well.

ah....

We've always used the tagline "Please join us for an adult celebration of blah blah blah"

Only had a couple calls to clarify.

aiki

Nothing wrong at all with specifying on the invitation that it is a big kids only affair......some folk are dense enough that they may not catch the cocktail thing.

The attached link has some good ideas

Here is a link that might be useful: How to say NO KIDS

I agree with SuzieQ ...Theres always one couple in the crowd that cant live without there kids for and evening. Believe me, I have had this situation happen to me! I now put on the bottom of the invitation "Adults Only Please!!!"
This way there no guess work. I have had a friend call and say we wont be able to come if I cant get someone to watch the kids...I say "oh no thats a shame maybe next time when we have all the kids and families...of course I dont say it rude but I will not open myself up to "Well lets see what happens" because it always seems to be the kid who want to run through my house like a nut job all night!! There is defiately a time and place for everything I can gaurantee you there is NO place for a kid at 9:00 at a cocktail party!!

How to specify "adults only" ??

Just write it down clearly like that, "adults only" in bold letters......

Be very specific in this day and age, my friends's son's wedding was overtaken by kids, and these peoople just brought their kids without even asking...young ones and teenagers... what are people thinking !!