The TV chef said his oldest girl, 11-year-old Poppy, is the only pupil in her class not to have a phone. And when he found out she and younger sister, Daisy, 10, had secretly opened photo-sharing Instagram accounts, he shut them down.
Jamie told Closer magazine: "I found out my two eldest girls had set up Instagram accounts in secret, which I wasn't happy about and soon put a stop to.
"Poppy is 11 now and the only girl in her class still not allowed a mobile phone. It may sound harsh, but I do worry about the bullying that can go on with these sites.
"I know the girls have had a hard time in the past at school because their dad's on television. I just don't want to risk it happening online too. It's impossible to keep an eye on."
The 38-year-old father of four, who has been married to the girls' mother Jools for 13 years, added: "I don't know how long I can keep them from social networking and away from smartphones but I will try for as long as I can."
In the past, Jamie has admitted his education was a 'struggle' because he was bullied because of his dyslexia.
He said: "I was in separate classes because of my dyslexia. It's hard for me to read and I have never read a book cover to cover.
"The kids sometimes used to shout 'special needs' at me."
And in June this year, he revealed he had been the victim of online abuse from a Twitter user 'being persistently horrible'.
He said: "Usually I don't rise to the bait, but this bloke was really getting to me.
"I managed to find out who he was, where he lived and who his mum and dad were, and it turned out that I was a good mate of his boss, too.
"Funnily enough, he stopped the abuse immediately when I posted his details up. I got a nice apology as well ... lesson learned, I think."
Parentdish has partnered with the charity BeatBullying. You can find out more here.