Waitākiri School's board brought in the rugby ban after a year six boy suffered severe concussion during a game last year.
School Board chair Ben Naylor said some kids at that age can weigh twice as much as others, which makes tackling dangerous.
"As long as you've got big kids running over little kids, where is the fun in that for the little kids?"
Ben Naylor said the school isn't 'anti rugby' and the ban is based solely on safety.