Around three in 10 parents find it hard to control the amount of time their children spend in front of screens, according to a poll.
And many mums and dads are concerned that screens are getting in the way of children being active.
The poll, which questioned just over 1,000 parents, also found that around one in four think their child prefers playing online games with their friends than being outside with them.
In total, 29% of those polled said they find it hard to control how much screen time their child is getting.
More than half (59%) agreed that screens are getting in the way of children enjoying playing outside or being active.
But at the same time, nearly one in five (18%) said they believe their youngster is safer playing online games than playing outside.
Some 28% said their child prefers playing online games with friends than playing outside with friends, while just over a fifth (21%) said their son or daughter prefers playing E-sport games to physically playing sports.
Ronnie Heath, managing director of PE training provider Create Development, which commissioned the survey, said: "PE and Sport is a fantastic vehicle not only to improve health and fitness but also to develop a range of personal, social, physical, cognitive and creative abilities, and it is important that these abilities are harnessed from a young age.
"Through simple activities and games, physical activity can easily be built into children's daily routine."
:: The Censuswide survey questioned 1,063 parents with children of any age between September 13-16.