The threat occurred in December last year at a pre school in southern Sweden.
The convicted man had heard that his own son, a two-year-old, had been hit by another child. When the father arrived at the school, he became aggressive when he saw the child playing with a teacher.
"Hit him. If you don't, I will – and then I'll hit you," the man yelled, according to reports in the Metro newspaper.
Teachers restrained the man as at least ten children looked on.
"I'm going to go and get a pistol and come back to the school – then I'm going to shoot everyone," he added.
On Tuesday the man was convicted by the Lund District Court for making illegal threats, and was forced to pay damages to three teachers and the child he threatened.
He denied the accusations, but admitted that he "got angry" while defending his son.