As scientists are able to understand and manipulate ever smaller scales of matter, research in the fields of biotechnology and nanotechnology has converged to enable such radical innovations as lab-on-a-chip devices, targeted drug delivery, and other forms of minimally invasive therapy and diagnostics. This paper provides a descriptive overview of the emerging bio-nano sector, identifying what types of firms are entering, from what knowledge base, where they are located, and their strategic choices in terms of technological diversity and R&D strategy. The firms engaged in bio-nano research and development span the range from start-up firm to multinational pharmaceutical, biotech, chemical, and electronics firms: two thirds of bio-nano firms are relatively young and relatively small. The United States dominates this sector, with more than half of all bio-nano firms located in the USA. Even within this sector which epitomizes the convergence of technology, there is a broad range of technological diversity, with the most diverse firms overall coming from a base in electronics, the most diverse start-up firms coming from a base in nanomaterials, and the most narrowly focused firms coming from biotechnology/ pharmaceutical base. We find that hybridization has been the dominant knowledge diversity strategy, with 93% of the bio-nano firms with nano-patents holding multiclass patents.