Ms Walker, who was in town recruiting Green Party members at Clubs Day on Wednesday, said students - many of whom had just reached voting age - should choose the party which best matched their beliefs.
''I would encourage them to think about what their core beliefs are and look at political parties and see how they step up against those beliefs.''
Her call to get involved came amid a trend of low voter turnout - especially among young people.
''That's partly a challenge to us as politicians to make ourselves relevant and interesting to young people.''
Ms Walker, a former editor of Otago University student magazine Critic, said she enjoyed coming back to Dunedin.
''I have been coming to O-Week every year since I was elected. It is a great way to meet students and it's always nice for me personally, because I spent so much time here.''
Asked if O-Week had changed much since she was a student, she said: ''I feel older, but apart from that it's very familiar. I have very distinct memories of coming to clubs day and signing up for lots of different clubs.''
Speaking halfway through the day she said she was very happy with the number of people she had signed up to the Green Party, which attracted a lot of support from young people.
''Our supporters tend to be younger than the average population and students are a big part of that. ''Our policies, I think, are very good for students,'' Ms Walker said, and gave examples.
Among the policies she was pushing at the moment were reversing the changes to student allowances and improving rental accommodation, which she said was particularly relevant to Dunedin students.
''Thinking about some of the places I used to live, some of them are just shocking.''