Half of children (50%) think they have seen their parents drunk at some time, according to a survey published today.
Almost a third (30%) of children feel scared when they see adults drinking, the study for CBBC's Newsround discovered.
Nearly three-quarters of the children questioned (72%) said their parents drink alcohol.
Of those, seven out of 10 (70%) thought they had seen them drunk.
Just less than half of the children (46%) surveyed thought that adults should not drink in front of children, while 32% thought this was all right, and 22% were not sure.
When given a list of words to describe how they felt when they saw adults drinking, almost half the children (47%) said they were not bothered. But 30% said it made them feel scared.
Eight in 10 children (81%) surveyed who had seen adults drinking said they noticed one or more changes in the way they behaved.
Of those, almost a quarter (24%) said it made adults act stupid or silly; a fifth (20%) said they became angry and aggressive; another fifth (20%) said they became happy and funny; 19% found them to act strangely or in a different way; 18% said they became loud and swore; and 17% said they became dizzy or fell over.
The results will be revealed today on CBBC's Newsround on BBC1 at 4.55pm as part of a wider exploration of the issue of alcohol and how adults' drinking affects children's lives.
Damian Kavanagh, Controller of CBBC, said: "Newsround has a great track record in covering complex issues in an engaging and helpful way. There has been much discussion about levels of drinking but the social impact is rarely explored from a child's point of view.
"Alcohol is present in the lives of most of our audience in one way or another, yet it is something they may not feel confident talking about."
:: The survey was conducted by Childwise during April and May, using the Childwise schools panel online. Some 1,234 young people across the UK were asked questions about their views on alcohol and how it affected them.