For around fifteen years, companies have developed the international side of their R&D. What are the advantages which mean that, despite the potentially high distancing costs, companies choose to outsource all or part of their R&D? In theory, there are three motivations: learning, or an increased knowledge stock, the conquest of new markets or exploitation of existing stock, and finally access to lower research costs. The aim of this article is to determine the relative importance of these motivations for French companies. The 2003 Inter-company relations survey (Erie - Enquête sur les relations inter-entreprises) sheds more light on the R&D relationships between French companies and their partners, be they French or foreign. The results show that a complimentary relationship with an R&D partner, which fosters learning, is a determining factor when companies choose to internationalise their R&D. Access to new markets also has an impact, but a secondary one. Finally, the cost-reduction aim is not significant. In particular, up until now very few relationships with partners in low-cost countries have been observed.