A survey by the industry-funded charity Drinkaware found 46 per cent had seen their parents drunk, with 29 percent saying that they had seen it on more than one occasion, Sky News reported.
The poll of 1,000 parents and their children also found 42 per cent of parents admitting their child had seen them or their partner drunk.
But 72 per cent of parents said that they felt very confident talking to their child about drinking and 75 per cent believed that they were best placed to do so.
Elaine Hindal, chief executive of Drinkaware, said that while setting rules about alcohol and speaking to children about the risks is a positive step, equally important is that parents understand their significant influence as role models and feel confident to set a good example.
Estimates suggest that around one in three children under 16 in the UK live with an adult binge-drinker, and studies show that the odds of a teenager getting drunk double if they have seen their parents drunk - even if only on a few occasions, Hindal said.
She added that understanding the impact of what parents say as well as what they do is important, as both can shape children's attitudes towards alcohol.