These resources were first developed for use in Ethiopia where primary health care is delivered by Health Extension Workers (HEWs). In 2011, the Open University launched the HEAT (Health Education and Training) programme in which a team of academics from The Open University (OU) worked with Ethiopian health experts to develop a series of 13 modules covering a range of health issues. One of them, Non-Communicable Diseases, Emergency Care and Mental Health, included material on adult mental health, and a brief discussion of childhood mental health and developmental problems. In 2012, the charity Autism Speaks funded a team from the Open University’s (OU) Life, Health and Chemical Sciences Department and the Department of Psychiatry at Addis Ababa University (AAU) to research the knowledge, attitudes and current practice of rural HEWs on a range of adult mental health problems, and with a particular focus on childhood mental health and developmental problems. This research*, led by Dr Rosa Hoekstra at The Open University, now at King’s College London, revealed a need for more training in early detection, particularly in children (1), and specific support in tackling the stigma that may lead to affected individuals being concealed by their families, or to families with an affected individual being excluded by their community (2, 3). In response to these research findings the team from the OU and AAU, with the Ethiopian Federal Ministry of Health, produced the original version of the mental health guide and filmed the five short scenarios modelling a HEW interviewing mothers of children with autism or intellectual disability. In an evaluation, the research team found that these training materials had beneficial effects in countering HEWs’ negative beliefs about, and desire for social distance from autistic children (4). Although the resources were developed with Ethiopia in mind, most of the information and guidance can be readily used or adapted for use in other settings. The version of the Mental Health Guide offered here (version 1.2) is a selective revision of the original, prepared for an international audience by Dr Ilona Roth. Terms, practices and demographics which are specific to or specially relevant to Ethiopia are explained in brief footnotes throughout the guide. As Open Educational Resources, the Guide is free to download, use and adapt within a Creative Commons Attribution-NonCommercial-ShareAlike Licence