The world’s investment needs are huge. Just meeting the Sustainable Development Goals requires, annually, trillions of dollars. Massive private investment, including foreign direct investment (FDI), has to be mobilized for this purpose. However, especially the least developed countries simply lack the capacity to compete successfully in the highly competitive FDI world market to obtain the required funds. They need assistance – not only to obtain more FDI but sustainable FDI, to advance sustainable development. This paper raises the question of the need to define “sustainable FDI” and calls for an international support program for sustainable investment facilitation.