The Manukau Institute of Technology (MIT) in Otara started offering a free level three certificate in the Tongan language in July.
The school's deputy chief executive Pasifika, Peseta Sam Lotu-Iiga, said MIT's board agreed to prioritise Pacific learning outcomes late last year.
"Our belief is that if students are strong in their language, their culture and their heritage and understand where they come from and where they're going to, they're going to be more successful in the classroom and out in society," he said.
Seventeen students had signed up to the Tongan language paper and MIT planned to offer a level four certificate next year, said Mr Lotu-Iiga, who is a former National Party MP and Minister of Pacific Peoples.
"It's about strengthening student voices, recognising our Pacific language and culture on campus and celebrating the really good parts of Pacific communities here in Otara and around Manukau."