The practice of information systems/information technology (IS/IT) outsourcing is a major issue which has received much attention, as shown by the extensive literature on the topic. However, most works on outsourcing have focused on theoretical topics, and there are but a few empirical, quantitative studies. This chapter presents an empirical study of IS/IT outsourcing in Spain, which has been conducted along the lines of prior research carried out in different countries, and which focuses on the types, functions and targets of outsourcing contracts. We also attempt to examine the influence that this practice may have on the organizations’ management structure. A survey carried out on 530 Spanish firms has shown that 50% of Spanish large firms have outsourced part of their IS/IT, whereas outsourcing is practiced by 20% of medium-sized enterprises. Finally, it has been observed that the most frequently outsourced activities in Spain are hosting and Internet-related services.