Plant molecular farming has the potential to alter the biopharmaceuticals sector by providing novel options for vaccine manufacturing and therapeutic protein production. Plant viruses have emerged as a strong tool for biopharmaceutical manufacturing, with significant benefits over traditional approaches, and have the potential to transform biologics manufacturing and contribute considerably to the future of medicine and agriculture. Plant viruses are expression vectors that can be used to produce high-value pharmaceutical proteins such as vaccines and antibodies. Virus-like particles (VLPs) and virus nanoparticles (VNPs) act as carrier templates and target vehicles that display peptides and synthetic molecules, making ideal platforms for drug delivery. This chapter provides an overview of biopharmaceutical production in plants with plant viruses, with special emphasis on biotechnological advances in the field of viral vectors and agroinfection in molecular farming.