Urban health issues still do not get the attention they deserve in discussions of development or environment. Successful “development” is so intimately related to health – to measures that directly or indirectly help individuals, households or communities avoid or prevent disease, injury and inadequate food intake. Beyond an absence of disease or injury, “development” means the achievement of living and working conditions that underpin well-being. Environmental management is also intimately related to health, again in these two senses, either preventing or minimizing airborne, food-borne or water-related diseases and the effects of chemical pollutants and physical hazards, and ensuring good living and working environments that can contribute to well-being. Yet because so many of the measures that promote health and well-being fall to organizations that are not health agencies or do not understand their role as it relates to “health”, so little gets done. There are few measures with greater potential to transform well-being than a well-directed, participatory upgrading programme for “slums” or informal settlements for example, yet this is not seen as a health intervention. Indicators related to health are among the most powerful measures of the success of development and environmental management – for nations, for cities, for groups within cities. With regard to such measures as life expectancy at birth or infant, child and maternal mortality, cities around the world can be among the healthiest places – or among the most lifethreatening and health-threatening. There can also be enormous differentials in health indicators within cities. There are neighbourhoods within (say) Mumbai or Nairobi with health indicators that compare favourably with those in cities in high-income nations – but in each of these cities, around half the population lives in informal settlements and, in most such settlements, the indicators are dire. Urban health issues also do not get the attention they deserve in discussions of urban poverty and poverty reduction. Most official measures of poverty still include no direct consideration of health or of most of the key determinants of health. They attempt to define the income households need for adequate food consumption – but most do not assess the income needed to rent, buy or build safe, healthy housing and the associated infrastructure and services that are key determinants of health (for instance, safe sufficient water, good sanitation and readily available affordable health care). Most national and city governments give a low priority to addressing the social determinants of health. This editorial focuses on four health issues that are highlighted by papers herein – the failure of national and urban governments to address health (and its determinants); the inequalities within cities and between cities with regard to good health; the question of whether and where there is an urban penalty for health; and the measures that city governments can take to address health issues. Readers interested in urban health issues should also note that prior to this issue, Environment and Urbanization has published 86 papers with the word “health” in their abstract. There have been two previous special issues on urban health (Vol 5, No 2 (1993) and Vol 11, No 1 (1999)); and most other issues have dealt with key determinants of health, including Vol 15, No 2 (2003) on water, sanitation and drainage, Vol 16, No 2 (2004) on violence and security and Vol 19, No 1 (2007) on reducing risks from disasters and climate change.