One of the most difficult issues doctors face is a conflict between their professional duties. Such a conflict may arise when doctors know that information has implications not only for patients but also for family members but their duty of confidentiality prevents them from disclosing it. A comparative analysis of English and Israeli medical law reveals that the doctors' duty is based on two principles: a liberal perception of patient autonomy and an overriding utilitarian principle of prevention of harm. However, socio-medical research indicates that these principles do not entirely reflect the views of patients and doctors and are too narrow to deal with the complex situations in practice. Thus, it is argued that the doctor's legal duty of confidentiality should be reconsidered and qualified when it concerns the family. It is suggested that if medical law seeks to recognize the various interests family members have in genetic information then we should consider a different approach, founded on a relational interpretation of autonomy and communitarian notions of solidarity and moral responsibility. This approach perceives confidentiality and privacy as embracing the family unit, based on the view that close relatives are not entirely outside the private sphere of the individual but rather are integral to his or her identity. Thus, to the utilitarian mechanism available in medical law this approach adds a social criterion: The effect any decision (to disclose or not to disclose) will have on the familial relationship and on the dynamics of the particular family. This will provide a more flexible and workable alternative for doctors to resolve familial tensions over access to genetic information.