In accordance with the increasing role of international capital flows, especially foreign direct investment (FDI) for host countries, a rising concern about if this kind of capital could actually help countries to achieve their sustainable development aims. Besides undoubted benefits, especially for developing countries (such as bridging the gap of capital demand and supply for economic growth) that FDI could bring, there have been many cases of FDI that make the environment quality worse. This will for sure significantly affect the possibility of host countries to gain sustainable development goals. For that reason, this chapter attempts to estimate the impact of FDI on environmental quality (EQ) across a broad dataset of 230 countries worldwide. Applying the panel data techniques of fixed and random effects, we have found out the negative impact of FDI on EQ, proving the hypothesis of “pollution haven.” In addition, other results are also discovered, in particular: (i) based on the environmental Kuznets curve theory, there is an inverted U-shaped relationship between pollution levels and national income and (ii) the greater openness to trade leads to worse EQ, as the emissions of both CO2 and GHG increase.