Almost a third of six to 14 year olds illegally download US TV shows before they are aired in the UK, says New Media Age.
Research by the website revealed that Heroes, Lost and Glee, are among some of the most popular shows that are illegally downloaded.
Furthermore 16 percent of kids also admitted to illegally downloading films before they are released in the UK.
"We were incredibly surprised by how young these children are - for six-year-olds to be downloading is astonishing," Justin Pearse, editor of New Media Age, told the Evening Standard.
"Kids are leading the way when it comes to the convergence of broadcast television and the internet. Copyright and legality don't seem to be a barrier for kids - if they want to see something before it's on TV or DVD, they'll just get it online."
Pearse also warned parents they could be held responsible for their children's illegal file-sharing activities.
The UK government has already pledged to crack down on internet piracy by implementing a three-strikes rule that will see illegal downloaders issued with warning letters and emails. Repeat offenders could then be botted off the web.
The proposals will be set out in the Digital Economy Bill and will come into force in April 2010.