Good mental health is a learning enabler for adolescents, demonstrating a reciprocal relationship between mental health and learning outcomes. This article describes a Canadian participatory action research partnership between students, staff and a nurse researcher working together to explore student capacity-building experiences at an alternative high school. Fourteen themes including the importance of supportive healthy relationships within the school environment demonstrated what was happening that built capacity in students. We found that when students' voices were nurtured and they participated in school decision-making processes, a sense of capability resulted; often extending into long-term positive effects. Research outcomes were shared with key decision-makers including the Board of Education Trustees.