Worldwide, prevalence rates of students experiencing mental health difficulties are growing, with only one in five receiving treatment. The role of teachers in collaborative efforts both to identify and to provide effective services for these students is an essential one. However, scant research has explored the mental health literacy of pre-service teachers. In the present study, 186 pre-service teachers completed a vignette-based measure (Child or Adolescent version based on each teacher's experience) in order to assess their mental health literacy, comprised of beliefs and knowledge. Results indicate that participants expressed lower efficacy when teaching children or adolescents with externalizing as compared to internalizing behaviours but believed that a child or adolescent experiencing behaviours indicative of depression was of the greatest concern and in need of intervention. Pre-service teachers were able to correctly identify cases of anxiety and ADHD, but many attributed behaviours typical of depression to home life difficulties (Child version) or substance use/abuse (Adolescent version). Results are discussed in light of previous research in the field; recommendations for future research and practice are provided.