Despite the fact that the reasoning behind location of large pharmaceutical firms is largely known, the exact geographical configuration of their activities is largely unknown. The aim of this master's thesis is to identify this unknown geographical configuration of big pharma R&D and manufacturing units. By analysing this empirical data, areas of high concentrations of big pharma activity and trends in localisations can be identified. Following this, analyses from different perspectives have been carried out to explain certain aspects of these localisations and trends. The study is part of the Vinnova assignment by the Swedish Government to carry out an international study to shed light on the competitiveness of the Swedish sectorial innovation systems of pharmaceuticals, biotechnology and medical technology in international comparison.