Foreign direct investment (FDI) is known to play a role in the economic development of host countries through technology and skills transfers. It also has a knock-on effect on Private Domestic Investment (PDI). This is why it is particularly attractive to WAEMU countries, which are constantly integrating it into their development policies. However, the effects of FDI depend on the institutional framework in which it is undertaken. The objective of this paper is to analyze the effects of FDI on private domestic investment by highlighting the role of institutional quality.