Using the assumptions of various schools of thought on development as the theoretical framework, an attempt is made to examine the effects of foreign investment on the socioeconomic growth of 50 developing countries by means of multiple regression models that utilize some external and internal variables assumed to affect the growth rate of GNP. Results from these models indicate that new inflows of foreign investments and amounts of domestic investments are positively related to growth while accumulated stocks of foreign investments have no effect on growth. This suggests that development funds, designed specifically for increased domestic investments, would be the most effective way to increase GNP.