Virus-like particles (VLPs) are possibly the best candidates for safe, immunogenic, efficacious and inexpensive vaccines, for both animals and humans. Well-characterized human and animal viruses such as hepatitis B and C, HIV and papillomaviruses, rotaviruses, norovirus, foot-and-mouth disease viruses and even influenza A virus proteins have all been successfully investigated for VLP formation. Proteins have been produced in transgenic plants and via transient expression techniques; simple structures and structures depending on more than one protein, naked and enveloped particles, and peptides displayed on other viruses have all been made. There have been multiple proofs of concept, and more than a few proofs of efficacy. This chapter covers the history of VLP production in plants, and explores a few examples in detail to illustrate the potential of such a mode of production for human and animal medicine.