Close to 100 McNally High School students wore yellow T-shirts and pledged to join a national Special Olympics campaign to stop using the R-word on Monday.
Jenny Murray, a Special Olympian snowshoer, spoke to the crowd of students about how hearing the word "retard" affects her.
She remembers hearing the word used a lot more when she was younger, but she still hears it.
"It's derogatory, and it's offensive. You don't need to label people," said Murray.
The national #NoGoodWay campaign was created in 2014 to stop the casual use of the word in conversation.
Jordan Van Den Bruel, 15, pledged to join the campaign and not use the word. He also helped create a video that featured student testimonials about why they refrain from using it.
"There's kids that think it's just a word that doesn't matter, and they can say whatever they want because nobody really cares. But there are people that it does actually hurt," said Van Den Bruel. "People need to understand that what they're doing is actually harmful to others."
Const. Amanda Trenchard coaches Special Olympic athletes when she isn't working for the Edmonton Police Service. She has witnessed how the use of the word can affect people with disabilities.
"Years ago that word was used to describe them," Trenchard said. "It's not a good word. Now when they hear it they feel it's very negative.
"They become upset, some of them angry because they don't know how to express themselves. Why is somebody treating me that way? They're people just like you and I and they have amazing abilities."
The organizers of the event hope students will continue refraining from using the word and will encourage their friends and family to do the same.
According to Special Olympics Alberta, 850,000 Canadians live with an intellectual disability.