This article considers how the longstanding debate about patent law and biotechnology is playing out in the emerging field of synthetic biology. Synthetic biology draws on molecular biotechnology, chemical engineering, genomics, and information technology to create new tools and techniques with the potential to yield transformative applications in energy, medicine, and many other areas. There has been concern that very broad patents in synthetic biology could impede the development of innovative products and public access to them, thwarting the policy goals of the patent system. Some synthetic biologists are seeking patents, while others are sharing their work in order to avoid the pitfalls of the patent system. The article investigates whether synthetic biology raises new intellectual property issues, and whether law reform or new policies are required. It analyzes the likely impact of key United States case law, such as the Myriad decision on the patentability of synthetic biology technologies. The article argues that the major processes and tools in synthetic biology are likely to meet the legal tests for patentable subject matter. It then presents a detailed case study of the examination practices of the United States Patent and Trademark Office in relation to patent families filed by scientists at the J. Craig Venter Institute. The case study shows the patent system to be working well to narrow the scope of broad claims and avoid granting patents for technology too early in its development. The article further argues that there are significant differences between synthetic biology and earlier controversial subject matter, such as human genes and genetic tests. It concludes that while synthetic biology patents do pose possible risks to the goals of the patent system, they are likely to be less problematic in this regard than patents on earlier genetic technologies.