Stewart Ashton said he and his fellow flatmates tried to apply for a flat through a property management company recently, but received a text message saying the owner of the property would only accept "six studious females".
"Several days later, we were at a flat viewing with a different company, looking at two flats as part of a complex.
"We were told not to apply for one because the agent said it was ‘traditionally a girls’ flat, and we’d like to keep it that way’."
Mr Ashton said he and his flatmates were "frustrated", "maddened" and "disappointed" by the situation, because it had made the process of finding a flat much more stressful.
"We thought we were all good and the search was over, only to be maddened and disappointed that because we are five boys we had to keep looking," he said.
He believed it was happening because female students were being "stereotyped" as being cleaner than boys.
"Whether or not that’s true as a trend, it’s prejudicial to assume we are worse tenants due to our gender.
"We should be judged based on our actual reputation as tenants gained over the last year - not due to sexist stereotypes."
He and his flatmates were "good citizens" who had looked after their previous rental properties.
They had not had any noise complaints against them, and had kept their flat to a "reasonable level" of cleanliness.
"We are by no means the stereotypical party flat like you see on Castle St. We have respected our flat, and our [former] landlord agrees.
"Property owners should judge people applying by their references and former landlords, who know the character of those applying — not by what their chromosomes are, but by how they have historically treated property and people.
"Landlords should actually read the applications tenants send, get in touch with their references and make an educated decision from there, rather than taking short cuts and throwing out half your potential customers."
Property Investors’ Association Otago president Kathryn Seque said gender discrimination was illegal and urged students who had experienced it while applying for flats to contact the Human Rights Commission and the Ministry of Business, Innovation and Employment.
"It’s highly illegal and it shouldn’t be happening. I would encourage any potential tenants who are facing any sort of discrimination - whether it be gender, race, ethnicity, age, marital status - they should report it."
Female tenants were by no means always perfect, she said. They could be just as bad as male tenants.
"I had a group of girls about five years ago that decided to get up on the roof and repaint it, then leave paint all down the footpath for the council to clean up.
"But in this day and age, people are well aware that you should not and cannot discriminate against anything, and that includes gender and student flats."