Biotechnology is of strategic importance to modern capitalist societies, but is currently in a controversial and transitory phase of development. This thesis examines contemporary innovation in agro-food biotechnology. It identifies the products and processes associated with agro-food biotechnology, and the means by which they come about. In particular, it investigates the connections and interactions between various cultural, economic, political, scientific, social and technological elements in biotechnological innovation, some of the features of where and how innovation takes place, and the key actors and institutions that influence these arrangements and interactions. It treats innovation in agro-food biotechnology as a phenomenon embedded in broader human-technology relations, and develops a multi-dimensional approach to the understanding of biotechnological innovation. Using the spatial form of the network, biotechnological innovation is conceptualised as a multiplicity of networks which link various actors, activities and conditions together. Surveying and in-depth interview research techniques are employed to identify and examine these networks. The empirical work traces particular networks of biotechnological innovation from points in Denmark and the Netherlands, across Europe, to the UK. Five key findings are reached. First, there is an enormous discrepancy between current and potential developments in agro-food biotechnology as only a limited range of food processing aids and raw materials are being commercialised. Second, there is considerable uncertainty with the term 'biotechnology' which has practical implications for the developmental trajectories of biotechnology. Third, biotechnological innovation entails a diverse and ambiguous set of actors, activities and conditions whose ends are not readily predictable. Fourth, there is a dialectical relationship between agro-food biotechnology and the means by which it comes about, as biotechnological innovation shapes, and is shaped by, biotechnology. Fifth, biotechnological innovation not only involves connections and interactions between social and technological factors, but also entails cultural and existential exchanges.