All kids younger than 16 should be forced to wear helmets when they're out on their bikes, according to a group of top children's doctors.
At the moment it's not against the law to cycle without a helmet, but the doctors want that changed for kids.
More than half of all bike accidents involve children and helmets can prevent you getting seriously hurt.
But some experts think that making helmets compulsory would just put children off using their bikes.
And there have also been studies that say helmets can make life more dangerous on the roads, because they make cyclists think they're safer than they actually are.
Some say that can encourage cyclists to take bigger risks when riding.
This isn't the first time people have tried to get helmet wearing made compulsory. And it's unlikely the law will be changed anytime soon.