This paper argues the effectiveness of Ecohealth education for improving the quality of health and environmental education and for achieving sustainable development in developing countries. To illustrate the need for Ecohealth education, we review the transitions in health education, environmental education and Education for Sustainable Development (ESD) in various developing countries. Moreover, we discuss issues relating to these disciplines and consider the possible roles that Ecohealth education can play. Then, drawing on a case study conducted in Lao PDR, we propose a concrete example of the teaching content of Ecohealth education. We conclude that Ecohealth education can embody the concepts of ESD with respect to health and environmental issues, and thus can contribute to improvements in the quality of health and environmental education, and of ESD. In addition, we propose the following five actions for implementing Ecohealth education in developing countries: (i) promote research based on the approaches of public health and anthropology, and develop teaching materials that use the research results, (ii) empower school-aged children, (iii) encourage the active involvement and sharing of problems among communities, (iv) strengthen participatory teaching and learning methodology and (v) build a training system and train relevant teachers.