Focusing on bipolar disorders research, this article considers ethical issues of informed consent and privacy arising in genetic pedigree research at two stages: the construction of tentative pedigrees to determine family eligibility for study and, subsequently, the enrollment of subjects in and conduct of the family study. Increasing concern to protect the privacy of family members of primary subjects or probands, following ethical controversy over a survey study at Virginia Commonwealth University, has led some researchers and Institutional Review Boards (IRBs) to apply informed consent requirements to those represented on a tentative pedigree at the initial stage of research. This article analyzes the possible benefits, risks, and burdens to prospective subjects of seeking prospective consent for pedigree construction at this initial stage. It argues that the likely risk-benefit ratio favors granting a waiver of consent requirements for this stage of pedigree research and presents grounds for IRBs to grant such a waiver. The article closes by considering particular ethical concerns that should be addressed in the informed consent discussion when enrolling subjects in pedigree studies of bipolar disorder, including concerns about subjects' competence to consent, management of interim and incidental findings, and issues particular to psychiatric research.