Almost 40% of children are having more tantrums and outbursts during the lockdown.
A survey from Barnardos also found 84% of kids miss their friends and 68% miss school.
The charity's calling for the government to consider children's needs during the phased lifting of restrictions.
Chief executive Suzanne Connolly says it's not surprising kids are having more tantrums.
"We would consider the possibility of that being that the children are very worried, they're worried about the conversations that they're overhearing from their parents, they're worried about the fact their own routine has been disrupted.
"Children like to see their friends, they enjoy school and they enjoy their early years centre, and all that routine and structure is gone.
"They're also no longer seeing their extended family, so they're going to be more anxious, and children will express that through their behaviour."
