Developments in genomic science and biotechnology are creating new governance challenges concerning funding, oversight, and regulation of the underlying science and its applications. Among forms of genomics and biotechnology, human stem cell research has been one of the most controversial. It holds great promise for the development of medical therapies, but the link between human reproduction and research on embryonic stem cells has fuelled serious opposition. We contend that good policy design can reduce tensions around the advancement of controversial science and technologies flowing from it. This article examines issues in the governance of human stem cell research using evidence from California. Four lessons are drawn for the effective governance of other areas of human genomics and biotechnology. They are (1) isolate structural design from controversy; (2) make room for laypeople in the governance structures; (3) promote transparency, minimize secrecy; and (4) create opportunities for learning and innovation.