"Health sustainability is as critical as environmental sustainability". Discussing the state of health at the beginning of the 21st century is not dissimilar to discussing the state of the environment. Both are in crisis and run counter to the notion of sustainable wellbeing, both focus around the ways of life that have developed in our societies and both indicate that significant changes are required at the level of policy and of society. As regards the environment we have begun to realise that our way of life and use of energy is endangering the planet and its resources, and that it can endanger our health by destroying life support systems such as water. [Author] [Contents] : Introduction. - The process of ‘Thinking’ together. - Ten key directions forward. - Wellbeing: a central challenge for 21st century societies. - Healthy people-healthy economy. - Health and medical tourism. - Changing mindsets: addressing the determinants of health. - The classic determinants of health. - Determinants of Aboriginal health. - 21st century health determinants. - The key health sustainability challenges of 21st century societies.- Health in All Policies: The South Australian Health in All Policies approach. - Health in All Policies: the ten principles. - The next step: taking Health in All Policies to the local level. - Generation H!SA: investing in children. - The Generation H!SA model: a strategic approach. - The strategy: developing synergies and strengthening policy mechanisms. - Healthy public policy for children: a Children’s Health Act. - Generation H: their voice. - Health literacy: addressing the double inequity. - Health and wellbeing partnerships. - Mobility, health and equity. - Health, wellbeing and equity: Aboriginal health. - Body image and eating disorders. - Health research in South Australia: future directions. - Health research priorities. - Centre for Intergenerational Health.