The stimulation of innovation in the pharmaceutical industry through outsourcing of research and development (R&D) activities within the drug discovery and development process is analysed. The empirical data were collected through interviews with experts of pharmaceutical companies and service providers between 2002 and 2005. Additionally, in 2008, the outsourcing behaviour of the already interviewed and additional companies was analysed through desk research. The results show that the outsourcing behaviour of traditional and emerging pharmaceutical companies is completely different. Whereas the make-or-buy decisions of traditional companies are mainly competency or know-how driven, that of emerging companies are primarily capacity or cost driven. Nevertheless, for both types of companies the cooperation model of “strategic partnership” offers access to high-level expertise while reducing fixed costs and complexity. Within this model, external providers are temporarily integrated into internal R&D teams and thus able to support R&D projects flexibly and more timely.