Background: Information on physicians' illness behaviour is to a large extent based on studies of selected groups of physicians. The objective of this paper is to study self-treatment and help-seeking behaviour in a nationwide representative sample of physicians. Results: In total, 70% of 1,476 physicians answered a mailed, anonymous questionnaire as a part of the Norwegian Medical Association's health survey. Of these, 75% had performed self-treatment during the last three years. Treatment by spouse, friends, and colleagues was also frequent. Of those who used prescription medicine, 73% were self-prescribing it: 13% of the physicians had negative experiences with self-treatment. Some 56% stated that they would prefer to seek help for somatic problems from a physician to whom they had no personal ties, and 50% would seek help for mental problems elsewhere than in the mental health care facilities located where they lived. Conclusion: Most physicians practise self-treatment when they are ill, and although they prefer to be treated by a physician they do not have personal ties to, many contact friends and colleagues when they need help from another physician.