A new study shows kids who watch Sesame Street are more likely to keep up at school.

The academic study shows the programme is comparable to pre-school education.

Early Childhood Council chief executive Peter Reynolds says it's not entirely a surprise.

He says TV can be great for educational purposes if parents sit down with the child and engage with them - rather than use it as a distraction.

"Research indicates if you're just parking your child in front of a television set by way of a proxy for babysitting, that's not as good."

A study shows children under six watch about 40 minutes of television a day on average - that's around six million hours of TV watched by Kiwi kids before they start school.

Reynolds said in most cases the sorts of television designed for children's learning is best - like Sesame Street.

But he said parents have to be wary.

"So things that have an awful lot of violence in them, or don't seem socially appropriate, that's what you've got to be a bit more careful about."