This chapter focuses on a survey carried out in a group of the largest foreign investors in Slovakia. It aims to identify the internal and external change in Slovak companies, and the impact of foreign direct investment (FDI) on their restructuring. The research studies the impact of FDI on the restructuring of joint ventures and wholly-owned subsidiaries and the influence companies with FDI exert on other Slovak firms. The chapter examines the relationship between the volume of capital invested and the share of Slovak subcontractors. The share of Slovak subcontractors to 53 percent of the joint ventures and 60 percent of the wholly-owned subsidiaries is less than a half of the total deliveries. The fact that one-third of Slovak parent companies have not been able to profit from the presence of the foreign investor, shows their relatively low bargaining power and lack of experience.