Background Mental health disorders often begin in childhood and children spend a substantial amount of time in school. Adequately trained schoolteachers therefore have a role in the early identification of mental health issues in schoolchildren.

Aim To explore the experiences, knowledge and training needs of Irish primary school teachers in relation to mental health issues in their pupils.

Method This was a quantitative descriptive study with a cross-sectional design conducted in a convenience sample of primary school teachers in Ireland using an online survey sent to members of two teaching unions.

Results The mental health issues that respondents most often encountered in their pupils were anxiety, attention deficit hyperactivity disorder, autism and oppositional defiant disorder. Respondents had varying degrees of knowledge of symptoms of mental health issues and of mental healthcare for children. Most respondents had not received training in children’s mental health and were motivated to receive such training. Most respondents had positive attitudes towards supporting schoolchildren with mental health issues.

Conclusion There is an opportunity for mental health nurses to become involved in training and supporting primary school teachers to identify children’s mental health issues.