This paper aims to assess whether firms' strategies of R&D outsourcing determine changes in their internal R&D employment intensity. Four strategic decisions are investigated: to start, increase, decrease or stop outsourcing. It is found that internal R&D employment intensity decreases when firms decide to start or to increase R&D outsourcing. However, this finding hides important differences according to the type and location of the contractor.Starting to outsource to research centers in the proper region seems to decrease internal R&D employment intensity, whereas the opposite is true in case of outsourcing to firms and universities outside the proper region.