On Monday, Otago Boys’ High School rector Richard Hall announced at an assembly anyone caught swearing would receive an after-school detention.
Mr Hall said the rule was his idea and teachers would enforce it.
A pupil later told the Otago Daily Times the school should be focusing on more important issues instead.
Mr Hall said the swearing ban was put in place to ensure the school’s pupils were respectful in their language.
"Our opinion is that we want young men to behave themselves, speak respectfully to others, and to learn to really behave as what we would call mature young citizens.
"Swearing is something that isn’t respectful and isn’t necessary."
He said the swearing ban was among a raft of things that were about acting respectfully and like positive young men.
"We’ve highlighted how we expect our young men to behave ...
"Boys operate really well with structure and consequences and the idea really is that we are encouraging them as much as possible to not swear in this instance and this example, and if they do and they are heard and they get a detention they will accept it."
The pupil said the ban included swear words ranging from s... to the "f" word.
"I feel like it’s really dumb because it’s just how mates talk to each other these days.
"Even stuff like if you stub your toe and something pops out, what they’re trying to say is that you’re going to get a detention ...
"The way I see it really is they’re trying to build us into soldiers, like perfect human beings."
He said other school issues deserved more attention.
"There are so many other issues in the school such as bullying, fights ... and the biggest issue out of all of them is vaping and the school is doing very little about those things."
Mr Hall said the school did prioritise those issues and the swearing ban was a small example of things they did around positive masculinity.
