The success of the health care system depends on the accuracy, correctness and trustworthiness of the information, and the privacy rights of individuals to control the disclosure of personal information. A national policy on health informational privacy should be guided by ethical principles that respect individual autonomy while recognizing the important collective interests in the use of health information. At present there are no adequate laws or constitutional principles to help guide a rational privacy policy. The laws are scattered and fragmented across the states. Constitutional law is highly general, without important specific safeguards. Finally, a case study is provided showing the important trade-offs that exist between public health and privacy. For a model public health law, see www.critpath.org/msphpa/privacy.