GENETIC TESTS FOR SPECIFIC ADULT-ONSET DISORders (eg, breast and colon cancer) are now commercially available, and results of research studies for genetic polymorphisms that predict drug effects, for example, response to statin therapy, have recently been published. The failure to warn family members about their hereditary disease risks has resulted in 3 malpractice suits against physicians in the United States. This past year, the obligation, if any, to warn family members of identification of a cancer gene mutation was the topic of discussion among professional societies and advocacy groups. Concerns have been raised regarding the conflict between the physician’s ethical obligations to respect the privacy of genetic information vs the potential legal liabilities resulting from the physician’s failure to notify at-risk relatives. In many cases, state and federal statutes that bear on the issue of “duty to warn” of inherited health risk are also in conflict. This article discusses these issues and suggests that health care professionals have a responsibility to encourage but not to coerce the sharing of genetic information in families, while respecting the boundaries imposed by the law and by the ethical practice of medicine.