BACKGROUND: Local and global environmental problems are challenges to our societies and affect human health. This study examines how Norwegian physicians see these problems. MATERIAL AND METHODS: 1,260 physicians were sent a questionnaire on their knowledge, attitudes and practice related to this subject. The response rate was 88%. RESULTS: Four out of five physicians believe that the global environmental situation is a big threat to human health. Three out of five believe that physicians have a particular responsibility to contribute to a sustainable environment and development and should set an example by a sustainable lifestyle. Half of them believe that the health service has a greater responsibility for sustainability than other institutions. Only one out of three report that environmentally acceptable conditions have been focused in their workplace. Half of the general practitioners and one third of the specialists are faced with environmental health problems every week. More than every third doctor experience patients with "environmental hypochondria". Physicians feel that they need to know more about environmental medicine; mass media is their most important source of information. INTERPRETATION: The study indicates that Norwegian physicians understand the significance of the environmental situation and recognise the responsibility of the profession. However, this knowledge is to a lesser extent translated into practice.