This thesis is a collection of three empirical essays on foreign direct investment and cross-border portfolio investment. The objective of the first essay entitled: “Oil and the Location Determinants of Foreign Direct Investment in MENA Countries” is to investigate the effect of oil as a proxy for natural resources and the main location determinants of foreign direct investment. Moreover, this paper examines whether oil as a proxy for natural resources in the host countries alters the relationship between natural resources and institutional quality. The result of the interaction, which is the key interest in this chapter, is robust and undermines the effects of investment profiles on IFDI. Paying particular attention to the degree of outward FDI concentration in developing countries and transition economies, the second essay is titled “Extending Dunning's Investment Development Path (IDP): Home Country Determinants of Outward Foreign Direct Investment from Developing Countries.” The aim of the empirical estimates provided in this paper is to investigate the home countries’ determinants of outward FDI from developing countries. Results from the paper support the OLI paradigm, the IDP theory. In the third essay, “Cross-Border Portfolio Investment from the Developing Economies and the Top Major Partners, using the Gravity Model”, I have applied a new approach to a new panel data set of bilateral gross cross-border investment flows between 37 developing countries and 79 host countries. The remarkably strong results have positive implications for the theory of asset trade. The main result suggests that the positive and significant coefficient of GDP per capita in a destination country can explain a significant part of the Lucas paradox, and supports the reason for developing capital being invested outside the region. Interestingly, geographical proximity is found to exert a significant positive influence on assets in order that investors may seek to diversify their portfolios.