Compelling evidence from the last three decades clearly shows that transmissible spongiform encephalopathies (TSEs) develop as a result of a poorly understood misfolding event that converts the cellular prion protein (PrPC) to an isoform known as PrPSc which is aggregated, protease resistant and able to impose its aberrant conformation onto PrPC, leading to its accumulation in the central nervous system. Despite all the knowledge gathered in more than thirty years of research and the general understanding of the pathological processes, the molecular mechanisms remain elusive, making it difficult to develop rational therapeutic strategies for this group of incurable diseases. In this review article, we give an overview of what is known about prion architecture and how the limited structural information available has been used in the quest for remedies for these devastating disorders.