Patterns of disclosure of Huntington disease risk and genetic test results among family members are important, but have been underexplored. We interviewed 21 individuals in-depth - eight mutation-positive for HD, four mutation-negative, and nine not tested - for 2 hr each. Within families, critical questions arose of what, when, and to whom to disclose, and what to do post-disclosure. Interviewees wrestled with dilemmas of what to tell (e.g., suspicions vs. confirmed symptoms; initiation vs. completion of testing; partial vs. indirect information), how to disclose (e.g., planning in advance vs. "blurting out" information in arguments), and whether and how to tell extended family members. Questions arose of when to tell (i.e., to avoid disclosing "too early" or "too late"). Similarities and differences emerged related to types of relationships (e.g., parents telling offspring vs. offspring telling parents vs. siblings telling each other). Individuals often disclosed because of perceived duty to foster the health of their family members, enabling these others to pursue appropriate medical evaluation, if desired. Yet tensions arose because the information could burden these members, who also have rights to remain "in denial" if they wish and not discuss the topic or pursue testing. Post-disclosure, dilemmas emerged of whether and how much to encourage family members to pursue testing. These data shed important light on critical issues that have received little, if any, attention concerning what, how, and when disclosure occurs, and have key implications for at-risk individuals, genetic counselors, and other health care workers (HCWs), and for future research. At-risk individuals would benefit from considering these issues in advance. HCWs need to realize that these decisions are multi-faceted. Future research can explore whether, when, how, and how often HCWs raise these issues with individuals.