This study adopts a Social Network Analysis (SNA) perspective to investigate global R&D internationalisation patterns of the pharmaceutical industry. We use co-inventorships identified in pharmaceutical patents granted by the US Patent and Trademark Office (USPTO) between 1996 and 2013, giving rise to an international collaboration network by drawing a cross-country link when a patent lists at least two inventors located in different countries. We describe changing R&D internationalisation patterns by exploring network structures as a whole as well as the changing role of different countries. The results show that R&D internationalisation indeed has gained momentum in pharmaceutical innovation, in particular after the year 2006. The network has developed from a mono-centric, star-like network – with the USA constituting the only hub – to a more distributed and dense network. The relative decline of the USA has not taken place at the expense of emerging economies but at the expense of European countries. © 2015, © 2015 Taylor & Francis.