This article discusses "Family Secrets," a problem-based learning (PBL) curriculum module that focuses on the bioethical implications of genetic testing. In high school biology classrooms throughout New York State, students are using "Family Secrets" to learn about DNA testing; Huntington's disease (HD); and the ethical, legal, and social implications (ELSI) of genetic testing. Moreover, this article also discusses a five-part progressive disclosure PBL that includes: a family disease; the dilemma; a difficult choice; testing for the HD gene; and making decisions. Furthermore, some teachers reported that the module inspired them to create additional PBLs on topics such as ecology, evolution, and genetic engineering. Virtually all teachers stated that they would continue to use "Family Secrets" in the future and that it has indeed become a valuable addition to their genetics curricula. (Contains 3 figures.)