School nurses are involved in a complex framework of interactions with students, other professionals, parents and administrators. Trust between nurse and student is critical for interaction effectiveness. Little extant research examines trust in this setting, or interactions between students and nurses. The goal of this study was to understand through phenomenology the process of engendering trust in school nurse—high school student interactions. The qualitative approach explored school nurse perceptions of experiences interacting with students, yielding insights into nurse and setting based factors contributing to the development of trust. Subthemes within these included key behaviours and attributes enhancing trust engenderment in school nurse—student interactions. Interactionist analysis of nurse interactions allowed for the development of three models of school nurse effectiveness. Study findings were well supported by the extant nursing and psychological research literature. Nurses that purposefully strive to engender trust in young people will maximize adolescent health results.