Public acceptance of plant molecular farming (PMF) for therapeutic and industrial proteins is a contentious public issue with stakeholder concerns focused on the social, environmental and regulatory challenges surrounding their development. For the public, cross-pollination with food crops, safety, potential side effects on human health and regulatory and policing issues are areas that require careful consideration when balanced with the benefits of the technology. Moreover, there is public concern over transparency and the role of business, motivation for profits and ownership and access to PMF technologies. With this background, Pharma-Factory, a 4-year EU-funded research project from the Horizon 2020-Biobased Innovation for sustainable goods and services call, is investigating new ways of producing pharmaceuticals. Concomitantly, the work is tasked with ‘public engagement’ to explore barriers to acceptance of PMF pharmaceuticals for human and animal health. In this chapter, we present the research undertaken to achieve the main objective of ‘public engagement’, the value of the process for stakeholders and science and technology partners. The approach incorporated a variety of perspectives and the development of many tools, including visuals, a glossary, an icon language, a narrative animation, posters and interactive exhibits, all relating to the perceived value and concerns of the technology under development, highlighting lived experiences of those who would be the recipients of the technologies. This extensive methodological approach not only builds scientific capacity and curiosity, through a process of participatory deliberations, but also offers a rich story around the technology which, we argue, provides the circumstances for a ‘deep and meaningful’ dialogue with the public and an authentic voice which has a legacy beyond the public engagement inside the funded project. Crucially, as the subsequent sections reveal, the public engagement story did not shy away from or ‘hide’ inconvenient questions or concerns, but rather highlighted them as opportunities for further discussion.