The social benefits and costs of patents in new areas of technology are not always easy to elucidate. Law and policy reform bodies have been reluctant to recommend express exclusions from patenting, leaving this task to the courts. In recent times, the Supreme Court of the United States and the High Court of Australia have been interventionist in setting the threshold requirements for patentable subject matter. As yet, however, these issues have not been considered specifically in the context of 3D printing. This chapter examines Australian case law on gene sequences, software and business methods and methods of medical treatment, concluding that there remains considerable uncertainty on the thresholds of patentability. There is no certainty that software or business methods will continue to be patentable, and in the bioprinting area there is some doubt as to whether methods of treatment that utilise 3D printing will be patentable. The chapter then turns to an examination of the effectiveness of patent protection. This analysis shows that actions for primary infringement have limited scope, as do exceptions to infringement, although secondary infringement actions may have broader application.