The relationship between mental health and special educational needs is both complex and misunderstood. In this article, Richard Rose, Professor of Special and Inclusive Education, Marie Howley, Senior Lecturer, Ann Fergusson, Senior Lecturer, and Johnson Jament, a PhD student, all from the Centre for Special Needs Education and Research directed by Richard Rose at the University of Northampton, discuss findings from a national research project which explored the perceptions of pupil mental health needs by staff working in residential special schools. Teachers and other professional colleagues often feel ill-prepared to address mental health difficulties experienced by their pupils. This is, at times, exacerbated by a wider confusion when atypical behaviours are attributed to a diagnosed learning difficulty rather than being recognised as symptomatic of a mental health problem. The article suggests a need for clarification of the relationship between complex special educational needs and mental health and for increases in training opportunities and the development of resources for teaching about and supporting mental health and emotional well-being.